KR20230166088A - precipitation of metals - Google Patents

Abstract

The present invention relates in particular to a method for producing a co-precipitate comprising nickel, manganese and/or cobalt and to the co-precipitate produced by the method. A method for producing a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, comprising the steps of (i) providing an aqueous feed solution comprising the at least two metals and at least one impurity; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11 to produce (a) a co-precipitate comprising the at least two metals; and (b) providing a supernatant containing the at least one impurity.

Description

precipitation of metals

cross-reference

This application claims priority to Australian Provisional Patent Application No. 2021900570, filed on March 2, 2021, and Australian Provisional Patent Application No. 2021900571, filed on March 2, 2021, the contents of which are incorporated by reference in their entirety. It is included herein as.

In one embodiment, the present invention relates to a method of preparing a co-precipitate comprising nickel, manganese and/or cobalt and the co-precipitate prepared by the method. In another embodiment, the invention relates to a method of dissolving metals from a mixture for subsequent use in producing a co-precipitate.

It will be clearly understood that where prior art publications are mentioned herein, this reference does not constitute an admission that such publications form part of the general general knowledge of the art in Australia or any other country.

Lithium-ion batteries account for a significant portion of total portable battery sales worldwide, and battery sales more generally. Due to their high energy density, long lifespan, and light weight, they are often the battery of choice for a variety of applications, including electric vehicles, electric bicycles and other electric powertrains, and power tools. A particularly common combination of active materials in these batteries is nickel-manganese-cobalt, also called NMC (or NCM) materials. Different types of lithium-ion batteries use varying proportions of nickel, manganese, and cobalt. Batteries may also use just one of these elements, a combination of any two of these three, or combinations of one, two, or three of these elements with one or more additional elements such as aluminum and magnesium. there is. Different types of lithium-ion batteries use varying ratios of all of these elements.

NMC materials for batteries are typically produced by taking separate, high-purity individual salts of nickel, cobalt, and manganese and dissolving them all in solution in specific ratios and purities. A precipitation process is then performed on the solution so that the three metals co-precipitate as hydroxides, carbonates, or hydroxy-carbonates. This is widely considered the only way to achieve the high purity precursor product composition required for acceptable electrochemical performance. However, a drawback of this process is that impurity elements must be removed from the nickel, cobalt, and manganese feed materials before they can be used to produce battery materials. For example, NMC materials may require a purity level of 150,000 moles of NMC per mole of impurity element. Exemplary nickel sulfate for use in batteries contains less than 5 ppm of impurities, such as copper, iron, cadmium, zinc, and lead. As a result, producing pure salts of nickel, cobalt and manganese requires multiple separation and purification steps, which can be time and material (and therefore costly) intensive.

Nickel deposits typically have native nickel:cobalt ratios ranging from 10:1 to 100:1, and consequently the relative ratios of nickel, cobalt and manganese in these deposits typically require modification before NMC material can be produced. Nickel deposits typically contain a variety of other minerals, including iron, magnesium and silicate minerals, and therefore require significant processing before they can be used to produce NMC materials.

Another potential source of nickel, cobalt and manganese comes from used lithium-ion batteries. Lithium-ion battery disposal is receiving increasing attention from both economic and environmental perspectives as the battery market expands. Environmentally speaking, waste batteries contain high concentrations of metals such as nickel, cobalt, and manganese, and electrolytes containing volatile fluorine. As the demand for lithium-ion batteries increases and the need for material recycling increases, the cathode active material (CAM, or cathode active material) from waste lithium-ion batteries is of sufficient purity to be recycled for use in new lithium-ion batteries. There is a growing need to find better ways to recover NMC materials from black mass.

Lithium-ion batteries generally have five main components: casing, electrolyte, separator, anode, and cathode. The casing is usually a steel shell that houses all other components and has low economic value. Electrolytes are used to transfer charge through a battery and are made of a lithium-containing salt (usually lithium hexafluorophosphate or lithium tetrafluoroborate) dissolved in an aprotic organic solvent. A separator is typically a polymer membrane that separates the positive and negative half-cells of a battery. Lithium-ion batteries typically have a graphite anode connected to a copper current collector. Most of the battery's value comes from the cathode. Modern lithium-ion batteries have a cathode coated with an electrochemically active lithium compound containing cobalt oxide or a mixture of nickel, cobalt, and manganese (NMC). This cathode material is typically mixed with graphite and attached to the aluminum current collector using a binder.

Although various conditions have been attempted to recover NMC material from the cathode active material, it is difficult to recover nickel, cobalt and manganese without recovering significant amounts of unwanted impurities. Most of the NMC material recycling attempts to date have been aimed at producing separate nickel, cobalt and manganese salts for further use or producing highly purified solutions for further use.

Some battery applications may require the use of materials containing only two of, for example, nickel, cobalt and manganese, and the above considerations may apply to these materials as well.

In one embodiment, the present invention seeks to provide a process for preparing a co-precipitate comprising at least two of nickel, manganese and cobalt, which at least partially overcomes or substantially improves at least one of the above-mentioned disadvantages. Or, it may provide consumers with a useful or commercial choice. The co-precipitate may be suitable for manufacturing lithium-ion batteries. In another embodiment, the invention provides a precursor for use in the manufacture of lithium-ion batteries, such as a NMC material (particularly a cathode active NMC material) or a material comprising at least two of nickel, manganese and cobalt followed by It is desired to provide precipitates of one or two or all three of nickel, manganese and cobalt that may be suitable for use. In other embodiments, the present invention may be suitable for use (potentially after further processing) to produce a co-precipitate comprising nickel, manganese and cobalt, or partially overcome at least one of the disadvantages mentioned above. The goal is to provide a method of producing a solution that can be used to create a solution that is substantially improved or that can be useful to consumers or provide a commercial choice.

According to a first aspect of the invention, there is provided a method for producing a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising:

(i) providing an aqueous feed solution comprising the at least two metals; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2 to co-precipitate said at least two metals from the feed solution.

The following options and embodiments may be used individually or in any suitable combination with the first aspect.

The aqueous feed may contain at least one impurity. Accordingly, adjusting the pH of the feed solution may provide a supernatant containing the at least one impurity. Accordingly, in one implementation of the first aspect there is provided a method of producing a co-precipitate, wherein the co-precipitate comprises at least two metals selected from nickel, cobalt and manganese, the method comprising:

(i) providing an aqueous feed solution comprising the at least two metals and at least one impurity; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, thereby producing (a) a co-precipitate comprising the at least two metals; and (b) providing a supernatant containing the at least one impurity.

In one implementation, the method is a method of producing a co-precipitate, wherein the co-precipitate comprises at least two metals selected from nickel, cobalt, and manganese, the method comprising:

(i) providing an aqueous feed solution comprising the at least two metals and at least one impurity, wherein the at least one impurity is arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead. , silicon, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, and niobium. or is selected from the group consisting of combinations thereof; and

(ii) adjusting the pH of the feed solution to between about 6.2 and less than 10 to produce (a) a co-precipitate comprising the at least two metals; and (b) providing a supernatant containing the at least one impurity.

In one implementation, the pH of the feed solution is between about 6.2 and 11, or between about 6.2 and less than 11, or between about 6.2 and 10, or between about 6.2 and less than 10, or between about 6.2 and 9.2, or between about 6.2 and 8.5, or about 6.2. It is adjusted to 7.5.

In one embodiment, the total amount of at least two metals (or the total amount of nickel, cobalt and manganese) in the aqueous solution is less than 95%, especially less than 90%, or less than 85% or 80% of the total weight of the aqueous solution (especially the dry solids of the aqueous solution). is less than %, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, or less than 50%. In one embodiment, the total amount of metal complexes comprising at least two metals (or the total amount of metal complexes comprising nickel, cobalt and manganese) in the aqueous solution is less than 95%, especially less than 90%, of the total weight of the dry solids in the aqueous solution. or less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%. As used herein, the term “metal complex” may include, for example, sulfates of nickel, cobalt, or manganese. In one embodiment, the total amount of the at least two metals (or the total amount of nickel, cobalt and manganese) in the aqueous solution is greater than 1 ppb, especially greater than 1 ppm, or greater than 10 ppm, or greater than 100 ppm, or greater than 1,000 ppm, or greater than 2,000 ppb. ppm, greater than 5,000 ppm, greater than 10,000 ppm, greater than 20,000 ppm, or greater than 50,000 ppm.

As used herein, reference to “metal” or a particular metal (e.g., nickel, cobalt, or manganese) does not necessarily mean that it is in metallic (i.e., oxidation state 0) form. This reference includes all possible oxidation states of the metal, including its salts, unless the context clearly dictates otherwise.

As used herein, “at least one impurity” (which may be “at least one precipitated impurity”) is not nickel, cobalt, manganese, water, OH ⁻ , H ⁺ , H ₃ O ⁺ , sulfate, or carbonate. However, in one embodiment, the at least one impurity is not a complex of an anion with nickel, cobalt, or manganese (eg, sulfate, carbonate, or hydroxy-carbonate). In one embodiment, the at least one impurity is arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, It is selected from the group consisting of vanadium, lanthanum, ammonium, sulfite, fluorine, fluoride, chloride, titanium, scandium, iron, zinc and zirconium, or combinations thereof. In one embodiment, the at least one impurity is arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, Vanadium, lanthanum, lanthanides, actinium, actinides, titanium, ammonium, sulfite, fluorine, fluoride, chloride, scandium, iron, zinc and zirconium, silver, tungsten, vanadium, molybdenum, platinum, rubidium, tin, antimony, selenium. , bismuth, boron, yttrium, lead, niobium, or combinations thereof; In particular, arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, scandium, iron, zinc, zirconium, silver, tungsten, It is selected from the group consisting of molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium and niobium, or combinations thereof. In one implementation, the at least one impurity is (i) calcium and/or magnesium; (ii) alkaline earth metals; (iii) metal or metalloid species (not including alkali metals); (iv) metal or metalloid species that do not include alkali metal or anionic species (e.g., sulfate, sulfite, chloride, fluoride, nitrate, and phosphate); or (v) is or contains a metal or metalloid species that does not contain anionic species (sulfate, sulfite, chloride, fluoride, nitrate and phosphate).

In one implementation, the at least one impurity is at least 2 impurities, or at least 3 impurities, or at least 4 impurities, or at least 5 impurities, or at least 6 impurities. Such impurities may be as discussed herein.

In one embodiment, at least 1%, or at least 5%, or at least 10%, or at least 20% of said at least one impurity of said one or more impurities in the aqueous feed solution of step (i) or step (ii), or at least 30%, or at least 40%, or at least 50%, especially at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or At least 90% or at least 95%, at least 96%, at least 97%, at least 98% or at least 99% may be in the supernatant after co-precipitation, or in the washing solution after washing the co-precipitation, or in the supernatant and It may also be present in combination in both cleaning solutions. The at least one impurity may be a combination of impurities. The amount of each impurity in the aqueous feed solution that can be transferred to the supernatant may vary for each impurity.

In one embodiment, the molar ratio (or mass ratio) in an aqueous feed solution of at least two metals to at least one impurity (or at least one precipitated impurity) (or the molar ratio or mass ratio in an aqueous feed solution of at least two metals to all impurities (or The mass ratio)) is less than 300,000,000:1, or less than 200,000,000:1, or less than 100,000,000:1, or less than 10,000,000:1, or less than 1,000,000:1, or less than 500,000:1, or less than 250,000:1, or 200,000: less than 1 , or less than 100,000:1, or less than 50,000:1, or less than 10,000:1, or less than 5,000:1, or less than 1,000:1, or less than 500:1, or less than 200:1, or less than 100:1, or less than 50:1, or less than 25:1, or less than 10:1, or less than 1:1, or less than 1:10. The molar ratio (or mass ratio) in the aqueous feed solution of the at least two metals to the at least one impurity (or the mole ratio (or mass ratio) in the aqueous feed solution of the at least two metals to all impurities) is at least about 2,000,000:1, or at least about 1,000,000. :1, or at least about 100,000:1, or at least about 60,000:1, or at least about 30,000:1, or at least about 20,000:1, or at least about 10,000:1, or at least about 5,000:1, or at least about 1,000: 1, or at least about 500:1, or at least about 200:1, or at least about 100:1, or at least about 50:1, or at least about 10:1. This means the sum of the molar amounts (or mass amounts) of at least two or more metals, but may also mean one of at least one impurity, or the sum of the molar amounts (or mass amounts) of all such impurities. At least one, optionally more than one, and possibly all, of the impurities may be selected from the group consisting of calcium, magnesium, lithium, sodium, potassium and ammonium. In one implementation, the at least one impurity in the aqueous feed is selected from the group consisting of calcium, magnesium, iron, aluminum, copper, zinc, lead, sulfur, sodium, potassium, ammonium, and lithium.

It should be understood that references to metals herein do not imply that the metal is in the O oxidation state unless the context so indicates. For example, reference to nickel may mean any or all of Ni(0), Ni(II), and Ni(III), depending on the context. In one implementation, the at least two metals selected from nickel, cobalt, and manganese are all nickel, cobalt, and manganese. Nickel, cobalt and manganese may be in any suitable oxidation state. In one implementation, the at least two metals are selected from Ni(II), Co(II), and Mn(II).

In some embodiments, the feed solution of step (i) is less than 7.0, or less than 6.75, or less than 6.5, or less than 6.25, or less than 6.2, or less than 6.0, or 5.75, 5.50, 5.25, 5.0, 4.75, 4.50, 4.25 , 4.0, 3.75, 3.50, 3.25, 3.0, 2.75, 2.50 or a pH of less than 2.0. The feed solution of step (i) may have a pH greater than 2.0, or greater than 2.25, 2.50, 2.75, 3.0, 3.25, 3.50, 3.75, 4.0, 4.25, 4.50, 4.75, 5.0, 5.25, 5.50, 5.75, 6.0 or 6.2. there is. In certain embodiments, the pH of the feed solution in step (i) can be 1.0 to 4.0, 2.0 to 4.0, 4.0 to 6.0, 2.0 to 3.0, 3.0 to 4.0, 4.0 to 5.0 or 5.0 to 6.0, or 6.0 to 7.0. . In some embodiments, the pH of the feed solution of step (i) is 1.0 to 1.5, 1.5 to 2.0, 2.0 to 2.5, 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5. , or 5.5 to 6.0, or 6.0 to 6.5, or 6.5 to 7.0. The pH of the feed solution in step (i) may be about 2.5 to 3.5. It may be about 3.0.

The aqueous feed solution may be a leachate containing at least two metals selected from nickel, cobalt and manganese. Step (i) may include producing a feed solution. It may include producing leachate by the method described herein. In one implementation, the feed solution may be a leachate or a leachate may be used to provide an aqueous feed solution. In this embodiment, the term “used to provide an aqueous feed solution” can mean that the leachate is used directly as an aqueous feed solution, or that the leachate is further processed or treated and that the subsequently processed or treated solution is This may mean that it is the aqueous feed solution of step (i).

Accordingly, in an embodiment of the invention prior to step (i) the method may include (or step (i) may include) the following steps:

A. providing a feed mixture comprising at least one metal selected from nickel, cobalt, and manganese, the feed mixture being one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:

The oxidized feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2;

The reduced feed has more of the at least one metal in an oxidation state of less than 2 than in an oxidation state of greater than 2, or has substantially all of the at least one metal in an oxidation state of 2 and at least one of the metals in sulfide form. Have at least some of it; and

The unoxidized feed has substantially all of the at least one metal in the oxidation state of 2 and substantially none of the at least one metal in the sulfide form;

B. The feed mixture is treated with an aqueous solution to form a leachate comprising the at least one metal, wherein the pH of the aqueous solution is from about -1 to about 7 (or about -1 to about 6, or about 1 to about 7). , or about 1 to about 6), where:

If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and

If the feed mixture is a reduced feed, the treatment further comprises adding a reagent comprising an oxidizing agent;

The leachate thereby contains at least one metal in oxidation state 2.

In this embodiment, the phrase "has more" (e.g., in the phrase "the oxidized feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2") means should be considered 'having a greater molar concentration'. The term “substantially all” can mean at least 90%, at least 95%, at least 99%, at least 99.5% or at least 99%, respectively, on a molar basis. The various options and implementations described below may be used individually or in any suitable combination.

In one implementation, the at least one metal can be at least two metals.

In one implementation, step (i) includes:

providing a feed mixture comprising at least two metals, the feed mixture being one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:

The oxidized feed has more of at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2;

The reduced feed has more of the at least two metals in an oxidation state of less than 2 than in an oxidation state of more than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least one of the two metals in sulfide form. have some; and

The unoxidized feed has substantially all of the at least two metals in the 2 oxidation state and substantially none of the at least two metals in the sulfide form;

treating the feed mixture with an aqueous solution to form a leachate comprising said at least two metals, wherein the pH of the aqueous solution is such that the pH of the leachate is from about -1 to about 6 (or from about 1 to about 6), wherein:

If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and

If the feed mixture is a reduced feed, the treatment further comprises adding a reagent comprising an oxidizing agent;

This ensures that the leachate contains at least two metals in an oxidation state of 2,

To provide an aqueous feed solution, the aqueous feed solution is leachate.

Examples of oxidized feeds as defined above include mixtures of Ni(II), Co(III) and Mn(0) in a 5:2:1 molar ratio or Ni(III), Co(II) and Mn(0) in a 2:1:1 ratio. It may comprise a mixture of Mn(III) or Ni(II) and Mn(III) in any ratio without Co present. Examples of reduced feeds as defined above include mixtures of Ni(II), Co(II), and Mn(II)S in any ratio, or Ni(0), Mn(II), and Co(II) in a 5:2:1 molar ratio. ) may include a mixture of It should be noted that oxidation state (II) may be referred to herein as an oxidation state of 2 or +2 and these are used interchangeably. In one implementation, the leachate includes Co(II), Mn(II), and Ni(II).

In one implementation, nickel, cobalt and/or manganese laterite ores would typically be considered oxidized feed. In other embodiments, the mixed hydroxide precipitate, mixed carbonate precipitate, or oxide or carbonate of nickel, cobalt and/or manganese will typically be considered to be an oxidized feed or a non-oxidized feed. In one implementation, the nickel and/or cobalt sulfide ore or concentrate will typically be considered a reduced feed. In other embodiments, the mixed sulfide precipitate will typically be considered a reduced feed. In other implementations, ferronickel, nickel pig iron and nickel, cobalt and/or manganese metal alloys will typically be considered reduced feeds. In a further embodiment, material recycled from a lithium-ion battery would typically be considered an oxidized feed.

In one embodiment the mixture comprises nickel, cobalt and manganese, such that the aqueous solution comprises nickel, cobalt and manganese. In another embodiment, one of these metals is not present in the mixture, such that the aqueous solution contains two of nickel, cobalt and manganese and no other.

In one implementation, the feed mixture is an oxidized feed and the reagent includes a reducing agent. In another embodiment, the feed mixture is a reduced feed and the reagent includes an oxidizing agent. In a further embodiment the feed mixture is a non-oxidized feed and no reducing or oxidizing agents are used.

The previously published process uses a 4M sulfuric acid solution, a very strong acid with a pH below 0, for the leaching step. It is a highly corrosive acid and causes significant dissolution of impurity elements including iron, aluminum and copper. When elements such as iron and aluminum are dissolved, more acid is consumed in the leaching step, and their separation and/or removal in precipitation or separation and/or removal of other impurities consumes more base or other reagents.

In contrast, the leaching step described above involves treating the mixture in an aqueous solution at a pH of about 1 to about 7 or about 1 to about 6 (a pH 1 solution of sulfuric acid corresponds to about 0.05 M sulfuric acid). At this less acidic pH, the dissolution of iron, aluminum, and to a lesser extent copper will be less favorable. Conversely, nickel, cobalt, and manganese are all soluble below about pH 6 when they are in the +2 oxidation state. Use of this step provides a surprisingly effective and cost-effective way to prepare solutions suitable for co-precipitating at least two of Ni, Mn and Co with improved purity when compared to prior art approaches using more acidic conditions. do. It should be noted that one skilled in the art can readily determine, by routine experimentation and/or theory, the amount and concentration of a particular acid needed to achieve the target pH.

The mixture may be a solid mixture. This may be a mixture in which at least some of the nickel, manganese and cobalt are in solid form (eg a slurry). In one implementation, the mixture is a mixed hydroxide precipitate (or “MHP”). MHP is a solid mixed nickel-cobalt hydroxide precipitate that is a known intermediate product in the commercial processing of nickel-bearing ores. MHP may be derived from sulfide nickel ore, or laterite nickel ore. These MHPs can provide oxidized feed. This is because at least some of the manganese and cobalt in MHP may exist in oxidized form. MHP can be derived from crude oil recycling processes or from any nickel and cobalt containing aqueous solutions.

In one embodiment, the mixture is the product (generally a solid residue) obtained from the Selective Acid Leach (SAL) process disclosed in PCT/AU2012/000058, wherein the pH and the amount of oxidizing agent are determined by It is controlled so that some parts are selectively dissolved. The amount of oxidizing agent in this process is generally such that it oxidizes at least a portion of the cobalt and/or manganese to Co(III). As a result, use of this process generally provides an oxidized feed. As explained above, MHP is used in the SAL process.

Accordingly, in one implementation, prior to processing, the method:

(a) contacting an MHP comprising at least two metals with an acidic solution (which may contain an oxidizing agent) at a pH such that one of the metals (particularly cobalt) is stabilized in the solid phase and the other metal is soluble in the acidic solution; ordering step; and

(b) separating the solid phase from the acidic solution, wherein the solid phase comprises at least two metals and the solid phase forms at least a portion of the feed mixture.

In certain forms of this embodiment, these steps are:

(a) contacting the MHP comprising at least nickel and cobalt, and optionally also manganese, with an acidic solution (which may include an oxidizing agent) at a pH such that the cobalt is stabilized in the solid phase and the nickel is soluble in the acidic solution; and

(b) separating the solid phase from the acidic solution, wherein the solid phase comprises at least two metals, one of which is cobalt and the solid phase forms at least a portion of the feed mixture.

In this embodiment, the solid phase comprising the at least two metals may be a feed mixture.

In one implementation, the MHP is washed prior to step (a). MHP can be treated with an oxidizing agent in the washing step.

In one implementation, the feed mixture includes cobalt and nickel, and Step A includes:

(a) contacting the mixed hydroxide precipitate and/or the mixed carbonate precipitate comprising at least cobalt and nickel with an acidic solution comprising an oxidizing agent at a pH such that the cobalt is stabilized in the solid phase and the nickel is soluble in the acidic solution; and

(b) separating a solid phase from the acidic solution, wherein the solid phase comprises at least two metals, one of which is cobalt; wherein the solid phase forms at least part of the feed mixture.

In one embodiment, cobalt is stabilized in the solid phase in the form of Co(III). In one embodiment, the manganese is stabilized in the solid phase of step (a) in the form of Mn(III).

The pH of the acidic solution, or aqueous solution, or leachate in step (a) is from about 1 to about 6, or about 2 to 6, 2 to 5, 2 to 4, 2 to 3, 3 to 5, 3 to 6, 4 to 6. or 4 to 5, for example about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6. The pH(a) of step may be the final pH at the end of step (a). The pH of step (a) may be the pH of step (a) as a whole.

The oxidizing agent in step (a) or step B may be persulfate, peroxide, permanganate, perchlorate, ozone, mixtures containing oxygen and sulfur dioxide, oxide and chlorine; For example, it may be selected from the group consisting of sodium or potassium persulfate, sodium or potassium permanganate, ozone, magnesium or hydrogen peroxide, chlorine gas or sodium or potassium perchlorate. It may be persulfate or permanganate. It may be sodium or potassium persulfate, sodium or potassium hydrogen peroxide disulfate, or sodium or potassium permanganate.

In one embodiment of step (a), about 70% to about 500% of the stoichiometric equivalents of oxidizing agent are added relative to the combined moles of metals, such as cobalt and manganese, to be stabilized in the solid phase; For example about 80% to 400%; 80% to 200%, or 100% to 150%, for example about 70, 80, 90, 100, 110, 120, 125, 130, 140, 150, 200, 250, 300, 350, 400, 450 or 500 % is added.

The temperature of step (a) may be greater than about 20°C but less than about 120°C, or greater than about 50°C but less than about 100°C, or between about 60°C and about 90°C. This may be about 25, 30, 40, 50, 60, 70, 80, 90, 95, 100, 105, 110 or 115 degrees Celsius.

In step (b), the separation step may be a filtration step.

In one implementation, the method may include removing impurities from a feed mixture comprising at least two metals selected from nickel, cobalt, and manganese prior to processing. The method may include contacting a mixture (or precursor) comprising the at least one metal (or the at least two metals) with a mild acid leaching solution (which may provide at least a portion of the feed mixture). A weak acid leaching solution may contain about 0.005 M to about 0.5 M acid, or about 0.01 M to 0.3 M, 0.01 M to 0.1 M, 0.02 M to 0.08 M, 0.03 M to 0.07 M, 0.04 M to 0.06 M, or 0.0 5 M to 0.1 M. The concentration of the acid may be, for example, about 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4 or 0.5 M acid. In a weak acid leaching solution, the acid may be an inorganic acid or an organic acid. The inorganic acid may be selected from the group consisting of sulfuric acid, hydrochloric acid and nitric acid. The organic acid may be selected from acetic acid or formic acid. Other acids may also be suitable. The acid in the weak acid leaching solution may be sulfuric acid.

Step (a) may be carried out at any suitable pressure, generally atmospheric pressure. In step (a), a slurry may be provided. The slurry may contain from about 1 wt% to about 40 wt% solids, or from about 5 wt% to about 40 wt% solids, or from about 10 wt% to about 30 wt% solids, for example about 1, 5, 10, 15, 20 , may have 25, 30, 35 or 40 wt% solids.

After step (a), the solid can be separated from the liquid, for example by filtration. Solids can be used as the feed mixture in step B. Step (a) may be useful for removing and/or separating impurities selected from the group consisting of one or more of calcium, magnesium and zinc. This may additionally or alternatively remove and/or separate other impurities.

In another embodiment, the feed mixture is a product derived from or obtained from a lithium-ion battery, particularly a negative electrode material from a lithium-ion battery. It may also be derived from recycled NMC material. It may exceed the combined amount of nickel, cobalt and manganese by more than about 1 wt% or by about 2, 3, 4, 5, 10, 20, 30, 40, 50 or 60 wt% on a dry basis. It may comprise greater than about 0.1 wt%, or greater than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10, 20, 30 or 35 wt% nickel on a dry basis. It may comprise greater than about 0.1 wt% cobalt, or greater than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5 or 10 wt% cobalt on a dry basis. It may contain greater than about 0.1 wt% manganese, or greater than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10 or 15 wt% manganese on a dry basis.

Consequently, in another implementation, prior to the processing, the method may include separating the negative electrode material from the discharged lithium-ion battery. The separation step may include shredding or pulverizing the battery. The disconnection step may include removing the casing of the lithium-ion battery. The separation step may include separating the casing, electrolyte, anode, and cathode. The separated cathode material may form a mixture to be treated, or the mixture to be treated may be derived from the separated cathode material in the method of the first aspect.

When the cathode material is manufactured, the cathode is calcined to oxidize nickel, cobalt, and manganese. As a result, once the cathode is used and recycled, the spent cathode material is in a chemical state very similar to the SAL process residue. Accordingly, the used cathode material can be used in the method of the first aspect of the present invention.

In one implementation, the mixture to be treated may be the product (particularly the solid residue) obtained from the selective acid leaching (SAL) process disclosed in PCT/AU2012/000058 (as described above); Products from recycled lithium-ion batteries; Products from recycled NMC materials; Or it may be a combination thereof.

In one implementation, the feed is a mixture. In another embodiment it is a filter cake, for example a wet filter cake. In another embodiment, it is a slurry. The slurry may contain from about 1 wt% to about 40 wt% solids, or from 5 wt% to about 40 wt% solids, or from about 10 wt% to about 30 wt% solids, for example about 5, 10, 15, 20, 25, Can have 30, 35 or 40 wt% solids.

In the process of this embodiment comprising steps A and B, at least a portion of the at least one metal (or at least two metals) selected from nickel, cobalt and/or manganese in the feed mixture is in an oxidized state, i.e. in an oxidation state of greater than 2. It may be a state. As discussed above, a significant portion of the nickel, manganese, and cobalt present in the solid residue obtained from the SAL process may be in an oxidized state. Due to the low solubility associated with these oxidized metal components, the solubility of these metals in aqueous solutions at a pH of about 1 to about 6 can be significantly improved through treatment with a reducing agent. As a result, cobalt, manganese, and nickel reduced to the oxidation state of 2 can be selectively dissolved in an aqueous solution with respect to one or more impurities (or leaching impurities) in the solution.

In one embodiment, at least about 5%, 10%, 20%, 30%, 40%, 50% or 60% of at least one metal (or at least two metals) selected from cobalt, manganese and nickel in the treated feed mixture. % is in oxidized state.

Oxidized forms of cobalt include Co(III) and/or Co(IV); In particular, it may include Co(III). Oxidized forms of manganese include one or more of Mn(III), Mn(IV), and Mn(V); Generally, it may contain Mn(III). Oxidized forms of nickel may include Ni(III) and/or Ni(IV), generally Ni(III). The mixture may also contain significant amounts of cobalt, manganese and/or nickel in the desired (II) state.

However, the solubility profiles of some of the major leaching impurities in the solid residue, especially iron (Fe), aluminum (Al), and to a lesser extent copper (Cu), overlap to some extent with the solubility profiles of the desired nickel, manganese, and cobalt components. For example, the desired +2 oxidation state forms of nickel, manganese, cobalt, and iron (Fe(II)) are all relatively soluble between about pH 3 and about 7, whereas the oxidized forms of these metals are relatively soluble at about pH 3. It begins to dissolve significantly in aqueous solutions below. In the case of aluminum and copper, none of these leaching impurities have the same oxidation/reduction behavior as nickel, manganese and cobalt, but they are significantly soluble in aqueous solutions below pH about 3 and about 4, respectively.

In one implementation, the feed mixture may include one or more leaching impurities. One or more leaching impurities consisting of iron, aluminum, copper, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, fluoride, phosphorus, sodium, silicon, scandium, sulfur, titanium, zinc, arsenic and zirconium. Can be selected from the group.

It will be appreciated that, in most cases, the type and amount of these leaching impurities will largely depend on how much treatment the solid residue has undergone before the process is performed and what material is used as the starting material. For example, if solid residues are obtained directly from the SAL process, the residues are likely to contain significantly more iron (Fe) and aluminum (Al) than residues obtained directly from the cathode active material (CAM) itself. This is especially true if the CAM has first been partially processed through a recycling process.

In one implementation, the aqueous solution used for treatment includes a leaching agent. The leaching agent may be an acid. Acids can be used to provide a pH of about 1 to about 7, or about 1 to about 6. The leaching agent may be an inorganic acid or an organic acid. The inorganic acid may be selected from the group consisting of sulfuric acid, hydrochloric acid and nitric acid. The organic acid may be selected from acetic acid or formic acid. Other acids may also be suitable. The leaching agent may be sulfuric acid.

Aqueous solutions have a pH of less than 7.0, 6.75, 6.50, 6.25, 6.0, 5.75, 5.50, 5.25, 5.0, 4.75, 4.50, 4.25, 4.0, 3.75, 3.50, 3.25, 3.0, 2.75, 2.50 or less than 2.0 (or pH of leachate can be made to have). Aqueous solutions greater than 2.0, or 2.25, 2.50, 2.75, 3.0, 3.25, 3.50, 3.75, 4.0, 4.25, 4.50, 4.75. The pH may be greater than 5.0, 5.25, 5.50 or 5.75 (or may have a pH of the leachate). In certain embodiments, the aqueous solution may have a pH of 1.0 to 4.0, 2.0 to 4.0, 4.0 to 6.0, 2.0 to 3.0, 3.0 to 4.0, 4.0 to 5.0 or 5.0 to 6.0, or 6.0 to 7.0 (or the pH of the leachate can be adjusted to can have). In some embodiments, the aqueous solution has 1.0 to 1.5, 1.5 to 2.0, 2.0 to 2.5, 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5, or 5.5 to 6.0, or 6.0 It may have a pH of from 6.5 to 6.5, or from 6.5 to 7.0 (or may have a pH of the leachate). The pH of the aqueous solution may be about 2.5 to 3.5. It may be about 3.0. The inventors discovered that when the pH is below 1, more leaching impurities are dissolved in the aqueous solution. However, if the pH is higher than 6 or 7, the ability of the aqueous solution to dissolve nickel, cobalt, and manganese in the desired +2 oxidation state form is reduced. The pH of step B may be the final pH of the solution at the end of step B, i.e. the pH of the leachate at the end of step B. The pH of step B may be the pH of the entire step.

In one implementation, the method may include adding a leaching agent to the aqueous solution. Other embodiments may include adjusting the pH of the aqueous solution. In one embodiment, the pH of the aqueous solution can be controlled through the addition of an acidic leaching agent as defined above. In other implementations, the pH of the aqueous solution can be controlled through the addition of a base. Exemplary bases may include alkali or alkaline earth metal hydroxides such as sodium hydroxide. However, the base may be a nickel, cobalt or manganese containing material, for example a fresh solid (mixture to be treated, or a nickel, cobalt and manganese precipitate, for example a hydroxide precipitate) or a hydroxide compound or a carbonate compound or a hydroxy-carbonate compound. The advantage of using nickel-, cobalt- or manganese-containing materials, especially those containing at least oxidized parts, is that their addition also consumes the reducing agent remaining in the solution, and Fe ³⁺ is more concentrated than Ni or Co. As it precipitates more favorably, the conditions switch to oxidation, oxidizing Fe ²⁺ to Fe ³⁺ .

In one implementation, the leaching agent is added to the aqueous solution (or “leaching solution”) at a controlled rate. In one implementation, the leaching agent may be added gradually until the solution reaches the desired final pH (the desired final pH may be as described for pH of aqueous solutions above). In another embodiment, all leaching agents can be added to the aqueous solution in one step. In other implementations, the leaching agent may be added gradually during the course of treatment (i.e., over a predetermined period of time as discussed elsewhere herein). In some implementations, the reagent is combined with the aqueous solution and then added to the feed mixture. In other embodiments, an aqueous solution is added to the feed mixture to achieve the desired pH followed by addition of the reagent. In another embodiment, the reagent is combined with the aqueous solution after the aqueous solution is combined with the feed mixture.

The leaching agent may be added to the aqueous solution at a rate of about 10,000 moles to about 20,000 moles per ton of the mixture comprising nickel, cobalt and manganese; For example, at a rate of about 12,000 to about 17,000 moles of leaching agent per ton of mixture comprising nickel, cobalt and manganese; Alternatively, it is used at a rate of 14,000 to 14,500 moles of leaching agent per ton of the mixture containing nickel, cobalt and manganese. Sulfuric acid may be added to the aqueous solution at a rate of about 1.0 to about 2.0 tons H ₂ SO ₄ per ton of the mixture comprising nickel, cobalt and manganese; or at a rate of about 1.2 to about 1.7 tons H ₂ SO ₄ per ton of the mixture comprising nickel, cobalt and manganese; Alternatively, it is used at a rate of about 1.4 t H ₂ SO ₄ per ton of a mixture containing nickel, cobalt and manganese.

Reducing agents include hydrogen gas, SO ₂ gas, sulfites (e.g. sodium metabisulfite), organic acids, sulfides (e.g. nickel, sodium, potassium, cobalt or manganese oxides, or sodium, potassium, cobalt or manganese hydrogen sulfides). ) and hydrogen peroxide, or a combination thereof. This may be SO ₂ gas or sodium metabisulphite or a combination thereof. This may be SO ₂ gas. Combinations of reducing agents may be used. In one implementation, the reducing agent may be selected from the group consisting of hydrogen gas and SO ₂ gas. Advantageously, both hydrogen gas and SO ₂ gas are powerful enough to reduce cobalt, manganese and nickel and do not introduce additional impurities into the leaching solution. When selecting a suitable reducing agent, it is desirable to select a reducing agent that does not introduce impurities into the solution or introduces only impurities that can be easily removed and/or separated. In one implementation, the reducing agent is SO ₂ gas. If SO ₂ gas is present in solution, acids may be produced in situ (e.g. through reaction with solution or oxidized material). In one implementation, the reducing agent is a gas at atmospheric pressure and temperature. In other embodiments, the reducing agent is a liquid at atmospheric pressure and temperature. In a further embodiment, the reducing agent is a solid at atmospheric pressure and temperature.

Although sometimes one or both of these may be added over a period of 5 hours or more, the aqueous solution and, if used, the reagent can independently be added for about 0.25 to about 5 hours, or about 0.25 to 1, 0.25 to 0.5, 0.5 to 1, 0.5 to 2, 1 to 4, 1 to 3, 1 to 2, 2 to 5, 3 to 5 or 3 to 4 hours, for example about 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5 3, 3.5, 4, 4.5 or The addition can be done over 5 hours. These may be added independently or together. They may be added simultaneously, sequentially (if added batchwise or semi-continuously) or alternately. Each may be added independently, batchwise or continuously, or semi-continuously (i.e., added continuously but with periods without addition). The reagent is present in an amount of about 70 to about 500%, or about 100 to 500, 200 to 500, 300 to 500, 100 to 300, 70 to 200, 70 to 100 or 70 to 150% of the metal or metals to be oxidized or reduced. It may be added in stoichiometric proportions, for example about 70, 80, 90, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450 or 500%, although in certain cases proportions outside these ranges may also be used. It may be suitable.

In one implementation, the reducing agent is not hydrogen peroxide. The previously described process using hydrogen peroxide can oxidize any iron present and reduce nickel, cobalt, and manganese in the recycled cathode material. These processes use large quantities of hydrogen peroxide (hydrogen peroxide is a relatively weak reducing agent for nickel, cobalt and manganese). This means that there is little control over the reduction reaction. Moreover, hydrogen peroxide is a relatively expensive reagent and requires the addition of additional acid, and hydrogen peroxide also results in significant dilution due to the water involved.

The inventors have discovered that in order to selectively solubilize the oxidized forms of nickel, manganese and cobalt relative to the various leaching impurities in the mixture, it is desired that the oxidized forms of nickel, manganese and cobalt be soluble at a pH of about 1 to about 6. It has advantageously been discovered that conversion to the +2 oxidation state form is necessary.

In one implementation, the method may include adding a reducing agent to the aqueous solution. Other embodiments may include controlling the addition of a reducing agent to the aqueous solution. The addition of reducing agent to the aqueous solution can be controlled to substantially reduce the oxidized cobalt, manganese and/or nickel components to the desired +2 oxidation state while minimizing reduction of key leaching impurities such as iron (Fe), which In its Fe(II) form, it has a wide range of solubility and pH range. In one implementation, the method of the first aspect can be performed under conditions that preferentially reduce oxidized cobalt, manganese and/or nickel relative to leached impurities in the mixture. These leaching impurities include iron, aluminum, copper, iron, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, phosphorus, sodium, silicon, fluorine, sulfur, titanium, zinc and zirconium; In particular, it may be one or more (and in particular all of the groups) from the group consisting of aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc and zirconium.

The inventors have advantageously discovered that, in terms of the reduction reaction, the oxidized nickel should be reduced first, then the cobalt, then manganese and then iron. As a result, in one implementation the amount of reducing agent added to the mixture is selected to reduce the oxidized nickel, cobalt and manganese but not substantially oxidize the iron.

In one embodiment, about 0.5 to about 2 stoichiometric equivalents of reducing agent per combined mole of oxidized cobalt, oxidized manganese, and oxidized nickel (some of which may be free of oxidized metal) are added to the aqueous solution; or about 0.7 to 1.5, 0.8 to 1.2, or 0.9 to 1.1 stoichiometric equivalents. About 1 stoichiometric equivalent, or about 0.5, 0.75, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5 or 5 stoichiometric equivalents may be added. The inventors have advantageously discovered that generally one equivalent of reducing agent is sufficient to reduce one equivalent of nickel, manganese or cobalt in oxidized form. The reducing agent is used in a ratio of about 3,000 moles to about 10,000 moles of reducing agent per ton of feed mixture; Alternatively, it may be added to the aqueous solution at a rate of about 5,000 to 8,000 moles or 6,000 to 6,500 moles of reducing agent per ton of feed mixture. SO ₂ may be added to the aqueous solution at a rate of about 0.2 to 0.6 tons of SO ₂ per ton of feed mixture; or at a rate of 0.3 to 0.5 tons of SO ₂ per ton of feed mixture; For example, a ratio of about 0.3, 0.4 or 0.5 tonnes of SO ₂ per tonne of feed mixture is used.

In one embodiment, from about 0.5 to about 5 stoichiometric equivalents per combined mole of reduced cobalt, reduced manganese, and reduced nickel, some of which may be free of reduced metal; or about 0.5 to 2, 0.7 to 1.5, 0.8 to 1.2, or 0.9 to 1.1 stoichiometric equivalents of oxidizing agent are added to the aqueous solution. About 1 stoichiometric equivalent, or about 0.5, 0.75, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5 or 5 stoichiometric equivalents may be added. In one embodiment of Step B, the stoichiometric equivalent weight of oxidizer relative to the combined moles of reduced cobalt, reduced manganese, and reduced nickel (some of which may be free of reduced metal) is from about 70% to about 500%. Add %; For example, about 80% to 400%; 80% to 200%, or 100% to 150%, for example about 70, 80, 90, 100, 110, 120, 125, 130, 140, 150, 200, 250, 300, 350, 400, 450 or 500 Add %.

In one implementation, reagents (particularly reducing agents) are added to the aqueous solution (or “leaching solution”) at a controlled rate. Reagents (particularly reducing agents) may be added at a continuous rate over a certain period of time. Suitable times range from about 15 minutes to about 3 hours; or about 30 minutes to about 2 hours; or about 30 minutes to about 1 hour; or about 1 to about 3 hours; Or it may be about 1 hour to about 2 hours. We have found that slower addition rates generally provide greater selectivity for leaching impurities, while faster addition rates generally provide improved throughput.

In one implementation, processing is performed in a sealed container. Advantageously, the use of sealed vessels allows for controlled gas losses, allowing greater control over the reduction or oxidation reactions (if appropriate) and allowing for slower addition of reducing or oxidizing agents (in particular reducing or oxidizing agents). when the oxidizing agent is a gas). In one implementation, processing is performed at atmospheric pressure. In other embodiments, this is performed at a pressure of 0.9 to 2.0 atmospheres, or 1.0 to 1.5 atmospheres, for example about 1, 1.1, 1.2, 1.3, 1.4 or 1.5 atmospheres. Performing the treatment at a slight overpressure can be useful in limiting excess gases.

The inventors have discovered that for at least some reagents (e.g., some reducing agents) the addition of the reagent can affect the pH of the aqueous solution. As a result, in some implementations, the pH of the solution may need to be controlled, for example through the addition of an acid or base.

In some embodiments in which a reducing agent is used, control of pH and reduction reaction reduces leaching of iron, aluminum, and copper to less than about 40% by weight each; or would allow selective dissolution of nickel, cobalt, and manganese, while limiting them to no more than about 30%, 20%, 15%, or 12%, respectively. Advantageously, using this process a significant portion of some leached impurities can remain in the solid phase.

In another embodiment, the treatment includes leachate comprising dissolved nickel, cobalt and manganese, and iron, aluminum, copper, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, phosphorus, sodium, silicon, fluorine, sulfur, titanium, zinc and zirconium; or a solid comprising one or more (or all) of the group consisting of aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc and zirconium.

In one implementation, Step B is carried out at a temperature where the aqueous solution remains in a liquid state. In one implementation, this is performed at a temperature of about 0° C. to about 100° C.; or about 10°C to about 100°C, or about 20°C to about 100°C, or about 40°C to about 100°C; More particularly from about 50°C to about 100°C; or at about 60°C to about 100°C. In other embodiments, it is a temperature of about 60°C to about 95°C (or about 60°C to about 90°C); or about 70°C to about 95°C, or about 75°C to about 95°C; or at about 80°C to about 95°C. In one implementation, this is performed at a temperature between about 0° C. and about 100° C.; or about 10°C to about 100°C, or about 20°C to about 100°C, or about 30°C to about 80°C; or about 40°C to about 70°C; or about 45°C to about 65°C; or about 45°C to about 80°C; or at about 50°C to about 60°C. This can be performed at about 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100°C or about 55°C. Since the reaction/process is generally exothermic, the temperature of the aqueous solution may increase over time.

In one embodiment, stage B is 80 to 81.0, 81.0 to 82.0, 82.0 to 83.0, 83 to 84.0, 84.0 to 85.0, 85.0 to 86.0, 86.0 to 87.0, 87.0 to 88.0, 88.0 to 89.0, 89.0 to 90 .0, 90.0 to It may be carried out at a temperature of 91.0, 91.0 to 92.0, 92.0 to 93.0, 93.0 to 94.0, or 94.0 to 95.0°C.

In one implementation, Step B may be performed for a predetermined amount of time. As explained above, the time required for processing of the first aspect can be affected by factors such as the temperature at which the reaction is performed, the pH of the solution, and the reagents. However, in one implementation, the treatment may be performed for at least about 10 minutes, or at least about 30 minutes, or at least about 1 hour, or at least about 2 hours. In one embodiment, it is, for example, about 30 minutes to about 6 hours, or about 30 minutes to about 4 hours, 1 hour to 4 hours, 1 hour to 3 hours, or 2 hours to 3 hours, about 2 hours or about It can be performed for 2.5 hours.

In one implementation, the treatment is carried out through mixing or agitation, for example agitation.

In one implementation, processing may be performed using at least one vessel. At least one container may be one container or two containers. The vessel may be a mixing vessel and may be configured to mix liquids (which may include entrained solids) therein. The vessel can be agitated. A stirrer may be included.

Treatment may be carried out with any suitable ratio of liquid to solid. In one embodiment, the solid-liquid mixture comprises at least about 1% solids (by weight), or at least about 2%, 3%, 4%, 5%, 10%, 15%, or 20% solids (by weight). can do. In one embodiment, the solid-liquid mixture comprises about 3 to about 25% solids (by weight), or about 4 to 20%, 1 to 10%, 3 to 7%, or 4 to 6% solids (by weight). can do. In one implementation, the feed mixture and the aqueous solution together form a slurry.

The method may include combining the feed mixture with an aqueous solution and then adding a reagent (such as an oxidizing agent or reducing agent) to the aqueous solution. The oxidizing agent may be a mixture comprising at least two of nickel, cobalt and manganese (i.e. the starting material to be processed). Manganese, carbonate or hydroxide salts (usually carbonate or hydroxide salts) may also be added at this stage. A suitable manganese salt may be MnCO ₃ . Suitable carbonates may be selected from the group consisting of MnCO ₃ , Ni(OH)(CO ₃ ) _0.5 , NiCO ₃ , CoCO ₃ , Co(OH) ₂ , Na ₂ CO ₃ and CaCO ₃ . Suitable hydroxide salts may be selected from the group consisting of Ni(OH) ₂ , Ni(OH)(CO ₃ ) _0.5 , NaOH and Ca(OH) ₂ . This step can generally be performed at any suitable temperature as previously described for processing. This step can be performed for any amount of time, for example from about 30 minutes to about 10 hours, or from about 3 hours to about 10 hours, or from about 4 hours to about 8 hours. There is no need to remove or separate leaching impurities such as magnesium, sodium, calcium and zinc at this stage. At this stage, all reducing agent remaining in the solution can be consumed.

In one implementation, the method may include adding an oxidizing agent and/or reducing agent to neutralize excess reducing agent and/or oxidizing agent in the solution. In other implementations, the method may include adding a base to the solution to increase the pH, e.g., above Step B but below pH 7 (e.g., pH 6). The method may include filtering the solution prior to neutralizing excess reducing and/or oxidizing agents or increasing the pH.

After treatment, impurities (or “leached impurities”) may be removed and/or separated from the leachate in any suitable manner. In this context, the term "impurity" or "leaching impurity" or "leaching impurities") refers to metals, complexes, compounds other than nickel, cobalt, manganese, water, OH ^- , H ⁺ , H ₃ O ⁺ , sulfate or carbonate. Or it means an element. An appropriate technique for removing impurities can be selected by one skilled in the art based on the nature of the impurities. For example, at least some of the leaching impurities may be in solid form. In one embodiment, the solid leaching impurities are removed and/or separated from the aqueous solution using at least one separation technique selected from the group consisting of decanting, filtration, cementation, centrifugation, and sedimentation, or a combination of any two or more thereof. It can be. Exemplary solid leaching impurities may include at least one selected from the group consisting of iron, aluminum, copper, barium, cadmium, carbon, chromium, lead, silicon, sulfur, titanium, zinc, and zirconium.

The leachate may contain at least one liquid leachable impurity. Exemplary liquid leachable impurities in the leachate include arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, vanadium, Lanthanum, ammonium, sulfite, fluorine, fluoride, chloride, titanium, scandium, iron, zinc and zirconium, silver, tungsten, vanadium, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, lead and niobium. or a combination thereof; In particular arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanum, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, It may be selected from the group consisting of antimony, selenium, bismuth, boron, yttrium, and niobium, or combinations thereof.

In one embodiment, the mass ratio of at least one metal (nickel, cobalt and manganese; especially selected from the group consisting of at least two metals or three metals):at least one liquid leachable impurity is less than 1:50 by weight. , or less than 1:20, or less than 10:1, or less than 1:1, or less than 10:1, or less than 100:1, or less than 500:1, or less than 1000:1, or less than 5000:1, or less than 10,000 :1, or less than 50,000:1, or less than 200,000:1, or less than 500,000:1.

In another example, at least some of the leaching impurities may be in liquid (or dissolved) form. In one embodiment, liquid (or dissolved) leachable impurities are ion exchanged, precipitated, absorbed/adsorbed, electrochemically reduced and distilled, or a combination of any two or more thereof, generally ion exchanged, precipitated and adsorbed, or a combination thereof. It may be removed and/or separated from the aqueous solution using at least one separation technique selected from the group consisting of combinations. In this context, the term “impurities” or “leached impurities” refers to metals that are not cobalt, nickel or manganese, but may also contain undesirable non-metals or metalloids. Exemplary liquid leaching impurities include arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, vanadium, and lanthanum. , ammonium, sulfite, fluorine, fluoride, chloride, titanium, iron, scandium, zinc and zirconium, or combinations thereof.

In one embodiment, the concentration of alkali metal (e.g., Na, Li, K) (or at least one alkali metal) liquid leachable impurity in the leachate is less than or equal to 100,000 ppm, or less than or equal to 80,000 ppm, or less than or equal to 60,000 ppm, or less than or equal to 50,000 ppm. ppm or less, or 40,000 ppm or less, or 30,000 ppm or less, or 20,000 ppm or less, or 15,000 ppm or less, or 10,000 ppm or less, or 7,000 ppm or less, or 5,000 ppm or less, or 4,000 ppm or less, or 3,000 ppm or less, or 2,500 ppm or less ppm or less, or 2,000 ppm or less. In other embodiments, the molar ratio of at least one metal (or at least two metals) to alkali metal liquid leachable impurity (or at least one alkali metal impurity) in the leachate may be greater than about 1:10 or greater than about 1:5; or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about It may be greater than 120:1, or greater than about 150:1, or greater than about 180:1, or greater than about 200:1. In other embodiments, the molar ratio of at least one metal (or at least two metals) to alkali metal liquid leachable impurity (or at least one alkali metal impurity) in the leachate may be less than about 1:1, or less than about 5:1; or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or about It may be less than 180:1 or less than about 200:1. In another embodiment, the molar ratio of at least one metal (or at least two metals) to alkali metal liquid leachable impurity (or at least one alkali metal impurity) in the leachate is from about 1:10 to 23,000:1, or about 1:10. to 100,000,000:1, or about 1:10 to 300,000,000:1.

In one embodiment, the concentration of anionic liquid leachable impurities (such as F ^- and Cl ^- (but excluding oxides, hydroxides, sulfates or carbonates)) (or at least one anionic liquid impurity) in the leachate is 100,000 ppm or less, or 80,000 ppm or less, or 60,000 ppm or less, or 50,000 ppm or less, or 40,000 ppm or less, or 30,000 ppm or less, or 20,000 ppm or less, or 10,000 ppm or less, or 5,000 ppm or less, or 4,000 ppm or less, especially 3,000 ppm or less, or 2,500 ppm or less, or 2,000 ppm. In another embodiment, the molar ratio of at least one metal (or at least two metals) to anionic species liquid impurity (or at least one anionic species liquid impurity) in the leachate is greater than about 1:10, or greater than about 1:5; or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or It may be greater than about 120:1, or greater than about 150:1, or greater than about 180:1, or greater than about 200:1. In other embodiments, the molar ratio (or mass ratio) of at least one metal (or at least two metals) to anionic liquid leachable impurity (or at least one anionic species impurity) in the leachate is less than about 5:1, or about 10:1. less than 1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1. may be less than or less than about 200:1.

In other embodiments, the concentration of alkaline earth metal liquid leachable impurities (e.g., Ca and Mg) (or at least one alkaline earth metal impurity) in the leachate is less than 50,000 ppm, or less than 40,000 ppm, or less than 30,000 ppm, or 20,000 ppm. less than, or less than 10,000 ppm, or less than 5,000 ppm, or less than 1,000 ppm, or less than 800 ppm, or less than 600 ppm, or less than 500 ppm, or less than 400 ppm, or less than 300 ppm, or less than 250 ppm, or less than 200 ppm It is less than. In a further embodiment, the molar ratio of at least one metal (or at least two metals) to alkaline earth metal liquid leachable impurity (or at least one alkaline earth metal liquid impurity) in the leachate is greater than about 500:1, or greater than about 1000:1; or greater than about 1500:1, or greater than about 2000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) to alkaline earth metal liquid leachable impurity (or at least one alkaline earth metal liquid impurity) in the leachate is from about 300,000,000:1 to about 1:10; or greater than about 1:10, or greater than 1:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) to alkaline earth metal liquid leachable impurity (or at least one alkaline earth metal liquid impurity) in the leachate is less than 1:10, or less than 1:5, or 1:10. Less than 1, or less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1 less than, or less than about 150:1, or less than about 180:1, or less than about 200:1.

In a further embodiment, the concentration of metal and metalloid liquid leachable impurities (or at least one metal or metalloid impurity) in the leachate is less than 250 ppm, especially less than 50 ppm. Exemplary metal and metalloid leaching impurities may be selected from the group consisting of iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, scandium, zirconium, and titanium. In one embodiment, the molar ratio of at least one metal (or at least two metals) to metal and metalloid liquid leaching impurities (or at least one metal or metalloid liquid impurity) in the leachate is less than 10,000:1, or 20,000:1. less than, or less than 40,000:1, or less than 60,000:1, or less than 80,000:1, or less than 100,000:1, or less than 500,000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) to Fe impurity in the leachate is from about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) to Fe impurity in the leachate is less than 10,000:1, or less than 20,000:1, or less than 100,000:1, or less than 500,000:1, or less than 1,000,000:1. It is less than. In one embodiment, the molar ratio of at least one metal (or at least two metals) to Al impurity in the leachate is from about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) to Al impurity in the leachate is less than 10,000:1, or less than 20,000:1, or less than 100,000:1.

In an embodiment of the invention, a method is provided for producing a co-precipitate wherein the co-precipitate comprises at least one metal selected from nickel, cobalt and manganese, the method comprising:

(i) providing a feed mixture comprising at least one metal and at least one impurity, the feed mixture being one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:

The oxidized feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2;

The reduced feed has more of the at least one metal in an oxidation state of less than 2 than in an oxidation state of more than 2, or has substantially all of the at least one metal in an oxidation state of 2 and at least one of the metals in sulfide form. have some; and

The unoxidized feed has substantially all of the at least one metal in the 2 oxidation state and substantially no of the at least one metal in the sulfide form;

treating the feed mixture with an aqueous solution to form a leachate comprising said at least one metal, wherein the pH of the aqueous solution is such that the pH of the leachate is from about 1 to about 7, wherein:

If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and

If the feed mixture is a reduced feed, the treatment further comprises adding a reagent comprising an oxidizing agent;

The leachate thereby contains at least one metal in oxidation state 2,

To provide an aqueous feed solution comprising the at least one metal, the aqueous feed solution is a leachate; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, thereby producing (a) a precipitate comprising said at least one metal; and (b) providing a supernatant containing the at least one impurity.

In this embodiment, the method may further comprise mixing at least one metal with the aqueous feed solution, wherein the at least one metal is selected from nickel, cobalt, and manganese, and step (ii) comprises nickel, cobalt, and manganese. and manganese.

In one embodiment, at least 1%, or at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 40% of said at least one impurity in the feed solution of step (ii). At least 50% of the at least one impurity, especially at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99% in the supernatant after co-precipitation, or in the wash solution after washing the co-precipitate, or in a combination of the supernatant and the wash solution. may be in The at least one impurity may be multiple impurities. The amount of each impurity in the aqueous feed solution, which may be in the supernatant, wash solution, or both, may vary from impurity to impurity.

In an embodiment of the invention, a method is provided for producing a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising:

(i) providing a feed mixture comprising at least two metals, the feed mixture being one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:

The oxidized feed has more of at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2;

The reduced feed has more of the at least two metals in an oxidation state of less than 2 than in an oxidation state of more than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least one of the two metals in sulfide form. have some; and

The unoxidized feed has substantially all of the at least two metals in the 2 oxidation state and substantially none of the at least two metals in the sulfide form;

treating the feed mixture with an aqueous solution to form a leachate comprising said at least two metals, wherein the pH of the aqueous solution is such that the pH of the leachate is from about 1 to about 7, wherein:

If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and

If the feed mixture is a reduced feed, the treatment further comprises adding a reagent comprising an oxidizing agent;

This ensures that the leachate contains at least two metals in an oxidation state of 2,

To provide an aqueous feed solution comprising the at least two metals, the aqueous feed solution is a leachate; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2 to co-precipitate said at least two metals from the feed solution.

In one implementation, at least one impurity in the co-precipitate can be controlled through selective precipitation. Less than 100%, or less than 90%, or less than 80%, or less than 70%, or less than 50%, or less than 30%, or 10% of the initial amount of at least one impurity in the aqueous feed solution that precipitates as a co-precipitate. There may be less, or less than 5%, or less than 1%. This is especially the case for alkaline earth metals such as Ca and Mg.

In one implementation, the at least one impurity may precipitate due to phenomena such as adsorption, absorption, displacement, atomic substitution, phase formation, secondary phase formation, mixed phase formation, co-precipitation, or liquid entrainment. The alkali metals (e.g. Li, Na and K), ammonia/ammonium, sulfur (in sulfate or sulfite form) and to a lesser extent the alkaline earth metals Zn and Cu can be removed by high purity water, acid, caustic, sodium carbonate or ammonia wash or these. It can be removed using a combination of . After washing, less than 100%, or less than 99%, or less than 90%, or less than 70%, or less than 50%, or less than 40%, or less than 30%, or less than 20%, or less than 10%, or less than 5%. , or less than 1% of these species may be present in the final co-precipitate relative to the amount in the aqueous feed solution.

In step (i), one or more impurities are removed at least partially from an aqueous solution comprising said at least two metals (in particular nickel, cobalt and manganese) in any suitable manner, for example as described elsewhere in the present application. In particular, it may be separated and/or removed (partially).

Accordingly, in a further embodiment there is provided a method of producing a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, comprising:

(i) providing an aqueous feed solution comprising the at least two metals and at least one impurity, and optionally removing and/or separating one or more impurities from the feed solution; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2 to co-precipitate said at least two metals from the feed solution.

In another embodiment, a method is provided for producing a co-precipitate comprising at least two metals selected from nickel, cobalt, and manganese, comprising the following steps:

(i) providing a feed mixture comprising at least two metals, the feed mixture being one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:

The oxidized feed has more of at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2;

The reduced feed has more of the at least two metals in an oxidation state of less than 2 than in an oxidation state of more than 2, or has substantially all of the at least two metals in oxidation state 2 and at least some of the at least two metals in sulfide form. have; and

The unoxidized feed has substantially all of the at least two metals in the 2 oxidation state and substantially none of the at least two metals in the sulfide form;

treating the feed mixture with an aqueous solution to form a leachate comprising said at least two metals, wherein the pH of the aqueous solution is such that the pH of the leachate is from about 1 to about 7, wherein:

If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and

If the feed mixture is a reduced feed, the treatment further comprises adding a reagent comprising an oxidizing agent;

This ensures that the leachate contains at least two metals in the second oxidation state;

to provide an aqueous feed solution comprising the at least two metals and at least one impurity, wherein the aqueous feed solution is a leachate, optionally removing one or more impurities (or at least a portion of the at least one impurity) from the feed solution; and /or separate; and

(ii) to co-precipitate said at least two metals from a feed solution (or (a) a co-precipitate comprising said at least two metals; and (b) a supernatant comprising at least a portion of said at least one impurity. adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2.

The step of removing and/or separating one or more impurities may be removing and/or separating one or more impurities from the leachate.

Appropriate techniques for separating and/or removing impurities to the desired degree may be selected by the skilled artisan based on the nature of the impurities. For example, at least some of the impurities may be in solid form. In one embodiment, solid impurities may be separated and/or removed from the feed solution (or leachate) using at least one technique selected from the group consisting of decanting, filtration, centrifugation, cementation and sedimentation, or combinations thereof. You can. Exemplary solid impurities may include at least one selected from the group consisting of iron, aluminum, copper, barium, cadmium, carbon, chromium, lead, silicon, sulfur, titanium, zinc, and zirconium.

In another example, at least some of the impurities may be in liquid (or dissolved) form. In one implementation, liquid (or dissolved) impurities can be removed by ion exchange, precipitation, absorption/adsorption, electrochemical reduction and distillation, or combinations thereof; In particular ion exchange, precipitation and adsorption, or combinations thereof; or removed from the feed solution (or leachate) using at least one separation technique selected from the group consisting of solvent extraction, ion exchange, precipitation, adsorption and absorption, or combinations thereof. Exemplary liquid impurities include iron, copper, zinc, calcium, magnesium, chromium, fluorine, lead, cadmium, silicon and aluminum; In particular, it contains iron, copper, zinc, calcium, magnesium, silicon and aluminum.

Ion exchange can be used to remove at least one impurity, especially at least one metalloid or metal (liquid) impurity, or alkaline earth metal (liquid) impurity. Exemplary impurities that can be removed using ion exchange include at least one of the group consisting of magnesium, calcium, aluminum, iron, zinc, copper, chromium, cadmium, and scandium; In particular it includes at least one of the group consisting of aluminum, iron, zinc, copper, chromium, cadmium and scandium. Ion exchange can be used to remove at least some of the zinc. Ion exchange can be carried out in at least two washing steps, especially in two washing steps. Ion exchange is carried out at a temperature of 20°C to 60°C; or about 30 to 50, 20 to 40 or 40 to 60° C.; For example, it may be carried out at about 20, 30, 40, 50 or 60°C. The pH of the ion exchange is about 2 to about 7, or about 3 to about 7, or about 3 to about 4, for example about 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 or 7. It can be.

Removal and/or separation of impurities may be performed using a combination of techniques to remove solid and/or liquid and/or gaseous impurities. Accordingly, it may include solid impurity removal and/or separation steps, and liquid impurity removal and/or separation steps. This may include gaseous impurity removal and/or separation steps.

In one implementation, removal and/or separation of impurities may be performed using at least one vessel. The at least one container may be one or two containers. The vessel may be a settling vessel and may be configured to settle liquid (which may include entrained solids) therein. The vessel may include at least two outlets. The vessel may include an upper outlet in an upper portion of the vessel to provide an outlet for liquid, and a lower outlet in a lower portion of the vessel to provide an outlet for settled solids.

In one implementation, step (i) may be performed using multiple vessels. In one implementation, step (i) comprises at least two vessels (or mixing vessels); In particular, it is performed using two vessels (or mixing vessels). In one implementation, the removal and/or separation of impurities may be accomplished using at least two vessels (or settling vessels); In particular, it is carried out using two vessels (or settling vessels).

In one implementation, a mixture comprising at least one or two of nickel, cobalt and manganese (or the feed mixture discussed above) is added to the aqueous solution of the first mixing vessel, especially while being stirred. The solution (including entrained solids) leaves the first mixing vessel through the first mixing vessel liquid outlet and enters the first settling vessel through the first settling vessel liquid inlet. The first settling vessel includes at least one upper outlet in an upper portion of the vessel to provide an outlet for liquid and a lower outlet in a lower portion of the vessel to provide an outlet for settled solids. The liquid leaving the first settling vessel through the top outlet proceeds to step (ii) of the method of the first aspect, or (as a further part of step (i) of the method of the first aspect) to remove liquid impurities in the solution. It can be done for. Liquid/solids exiting the first settling vessel through the lower outlet can flow into the second mixing vessel through the second mixing vessel inlet. A reducing or oxidizing agent and a leaching agent may be added to the second mixing vessel. In some cases there is no settling vessel and the solution is passed directly to the filter. The second mixing vessel can be agitated. The solution (including entrained solids) leaves the second mixing vessel through the second mixing vessel liquid outlet and enters the second settling vessel through the second settling vessel liquid inlet. The second settling vessel includes at least one upper outlet in an upper portion of the vessel to provide an outlet for liquid and a lower outlet in a lower portion of the vessel to provide an outlet for settled solids. Liquid exiting the second settling vessel through the upper outlet can flow to the inlet of the first mixing vessel. The liquid/solids leaving the second settling vessel via the lower outlet can be disposed of, for example after passing through a screw press. The advantage of this arrangement is that it minimizes the amount of acid and reducing or oxidizing agent remaining in the solution from which nickel, cobalt and manganese are co-precipitated. Additionally, the amount of iron (and other impurities such as copper and aluminum) in the first mixing vessel can be minimized by maintaining the correct conditions. In some implementations, the method may include the use of three or more mixing vessels (or reactors). The method may include controlling the amount of reagent added to any of the mixing vessels.

The method may include adding one or more of cobalt, manganese, and nickel to the feed solution or leachate to adjust the molar ratios of nickel, cobalt, and manganese to the desired molar ratio. Suitable desired molar ratios may include 1:1:1 nickel:cobalt:manganese, or 6:2:2 nickel:cobalt:manganese, or 8:1:1 nickel:cobalt:manganese. In some implementations, the desired molar ratios are 1:1:1 nickel:cobalt:manganese, 2:1:1 nickel:cobalt:manganese, 3:1:1 nickel:cobalt:manganese, 4:1:1 nickel:cobalt. :manganese, 5:1:1 nickel:cobalt:manganese, 6:1:1 nickel:cobalt:manganese, 7:1:1 nickel:cobalt:manganese, 8:1:1 nickel:cobalt:manganese, 9:1 :1 Nickel:Cobalt:Manganese, 10:1:1 Nickel:Cobalt:Manganese, 5:3:2 Nickel:Cobalt:Manganese, 9:0.5:0.5 Nickel:Cobalt:Manganese, or 83:5:12 Nickel:Cobalt : May contain manganese. Preferred molar ratios of nickel:manganese may include 1:1 nickel:manganese, or 6:2 nickel:manganese, or 8:1 nickel:manganese. In some implementations, the desired molar ratios are 1:1 nickel:manganese, 2:1 nickel:manganese, 3:1 nickel:manganese, 4:1 nickel:manganese, 5:1 nickel:manganese, 6:1 nickel:manganese. , 7:1 nickel:manganese, 8:1 nickel:manganese, 9:1 nickel:manganese, 10:1 nickel:manganese, 5:3 nickel:manganese, or 9:0.5 nickel:manganese. Preferred molar ratios of cobalt:manganese may include 1:1 cobalt:manganese, or 6:2 cobalt:manganese, or 8:1 cobalt:manganese. In some embodiments, the desired molar ratios are 1:1 cobalt:manganese, 2:1 cobalt:manganese, 3:1 cobalt:manganese, 4:1 cobalt:manganese, 5:1 cobalt:manganese, 6:1 cobalt:manganese. , 7:1 cobalt:manganese, 8:1 cobalt:manganese, 9:1 cobalt:manganese, 10:1 cobalt:manganese, 5:3 cobalt:manganese, or 9:0.5 cobalt:manganese. Preferred molar ratios of nickel:cobalt may include 1:1 nickel:cobalt, or 6:2 nickel:cobalt, or 8:1 nickel:cobalt. In some implementations, the desired molar ratios are 1:1 nickel:cobalt, 2:1 nickel:cobalt, 3:1 nickel:cobalt, 4:1 nickel:cobalt, 5:1 nickel:cobalt, 6:1 nickel:cobalt. , 7:1 nickel:cobalt, 8:1 nickel:cobalt, 9:1 nickel:cobalt, 10:1 nickel:cobalt, 5:3 nickel:cobalt, or 9:0.5 nickel:cobalt. In one implementation, the above-mentioned molar ratio may be the nickel:cobalt:manganese ratio or the nickel:cobalt ratio or the nickel:manganese ratio or the cobalt:manganese ratio in the co-precipitate. Not all of the nickel, cobalt or manganese in the feed solution precipitates. One skilled in the art will be able to select a suitable ratio based on the desired application and desired nickel:cobalt:manganese ratio in the final material (e.g., cathode material).

One or more of cobalt, manganese and nickel added to the solution may be in any suitable form. One or more cobalt-containing compounds, manganese-containing compounds, or nickel-containing compounds may be added to the feed solution. For example, the added cobalt, manganese and nickel may be in the form of one or more sulfate salts, hydroxide salts or carbonates, or mixtures thereof; In particular, it may be in the form of CoSO ₄ , NiSO ₄ and/or MnSO ₄ . In some cases, the feed mixture may be created by combining separate feed mixtures, each of which is independently an oxidized feed, a reduced feed, or a non-oxidized feed, to produce a composite feed for use in the presently described process. there is. In other cases, one or more leachates may be produced by the methods described herein using one or more feed mixtures, each of which is independently an oxidized feed, a reduced feed, or a non-oxidized feed, and the one or more leachates are then They can be combined in any suitable ratio to provide a composite leachate. In one implementation, metals other than Ni, Co, and Mn (in any suitable form) may be added to the leachate or aqueous feed solution. This may help create co-precipitates with the other metals present.

Step (ii) of the method produces a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese. In one implementation, the at least two metals selected from nickel, cobalt, and manganese are all nickel, cobalt, and manganese.

In one embodiment, at least one of greater than 1%, or greater than 10%, or greater than 20%, or greater than 50%, or greater than 60%, or greater than 80%, or greater than 90%, or greater than 99% of the co-precipitate. of the metals (in particular at least two metals, more particularly all nickel, cobalt and manganese) originate from the (leached) feed mixture. In one implementation, the feed mixture may be multiple feed mixtures that are combined. In one implementation, each of the plurality of feed mixtures may originate from a different source.

The pH of the co-precipitation step is about 6.2 to about 11, or about 6.2 to about 10.5, or about 6.2 to about 10, or about 6.2 to about 9.2, 6.2 to 9, 6.2 to 8, 6.2 to 7, 6.2 to 6.5, 6.5 to 9.2, 7 to 9.2, 8 to 9.2, 9 to 9.2, 6.5 to 9, 6.5 to 8, 7 to 9 or 7 to 8, for example about 6.2, 6.3, 6.4, 6.5, 7, 7.5, 8, A pH of 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9 or 10. If the feed solution from which at least two metals are co-precipitated is relatively pure, a pH of about 9 to 9.2 may be advantageous.

The inventors have found that a pH range of about 7.0 to about 8.6, or 6.2 to 8.6, is better than using a higher pH range, although the choice of pH will depend on the impurities present and their concentrations, such as magnesium salts and/or It has advantageously been found to be less likely to result in co-precipitation or incorporation of unwanted impurities such as calcium salts. For example, magnesium generally begins to precipitate as a hydroxide or oxide from solution above a pH of about 8.5, while calcium generally begins to precipitate as a hydroxide or oxide from solution above a pH of about 10.0 (but the complete Precipitation is not achieved until a higher pH is achieved and partial precipitation of these elements may be achieved at a lower pH depending on the precipitation method). As a result, co-precipitation can occur even at pHs where some impurities begin to precipitate. However, the relative amount of impurity precipitation can be controlled so as not to negatively affect the performance of the battery material, achieve a desired amount of co-precipitated impurities, or achieve desired battery material performance.

Any suitable reagent (e.g., base) may be used to adjust pH. Exemplary reagents (or bases) may include alkali or alkaline earth hydroxides such as sodium hydroxide. However, the base may be derived from nickel, cobalt and/or manganese containing material, such as fresh solids (e.g. hydroxides, carbonates or hydrocarbonates) or nickel, cobalt and manganese precipitates (especially hydroxide precipitates) produced by step (ii). It can be).

Step (ii) may be carried out at any suitable temperature or pressure. This can be done at a temperature and pressure where the feed solution is in liquid form. In one implementation, step (ii) is performed at about 15 to about 25° C., for example at about room temperature. In one implementation, step (ii) is performed at a temperature below about 100°C, or below about 90, 85, 80, 70, 60 or 50°C. In other embodiments, step (ii) is performed at a temperature greater than about 30°C, or greater than about 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80°C. In one implementation, step (ii) is performed at a temperature of about 25°C to about 100°C, or about 40°C to 95°C, 50°C to 95°C, 60°C to 90°C, or 70°C to 90°C. In one implementation, step (ii) is performed at a temperature of about 80°C. In another embodiment, step (ii) is performed at atmospheric pressure.

Step (ii) may be performed using any suitable base. In one implementation, the base can be carbonate, bicarbonate, hydroxide, ammonia, or mixtures thereof. It could be ammonia. Suitable carbonates may include carbonates selected from the group selected from ammonium carbonate, sodium carbonate, potassium carbonate, lithium carbonate, or mixtures thereof. Suitable bicarbonates may be selected from the group consisting of sodium bicarbonate, ammonium bicarbonate or mixtures thereof. A suitable bicarbonate is ammonium bicarbonate. Suitable hydroxides may be ammonium hydroxide or sodium hydroxide.

The at least two metals may co-precipitate in any suitable form, such as in the form of oxides, hydroxides, carbonates and/or hydroxy-carbonates.

The at least two metals can be all three of nickel, cobalt and manganese. They can co-precipitate in any suitable molar ratio. Exemplary molar ratios may include 1:1:1 nickel:cobalt:manganese, or 6:2:2 nickel:cobalt:manganese, or 8:1:1 nickel:cobalt:manganese. In some embodiments, the molar ratio is 1:1:1 nickel:cobalt:manganese, 2:1:1 nickel:cobalt:manganese, 3:1:1 nickel:cobalt:manganese, or 4:1:1 nickel:cobalt:manganese. , 5:1:1 nickel:cobalt:manganese, 6:1:1 nickel:cobalt:manganese, 7:1:1 nickel:cobalt:manganese, 8:1:1 nickel:cobalt:manganese, 9:1:1 Includes nickel:cobalt:manganese, 10:1:1 nickel:cobalt:manganese, or 9:0.5:0.5 nickel:cobalt:manganese.

Step (ii) may include separating the co-precipitate from the supernatant. This separation may include one or more of decantation or filtration. Separation may involve resuspending the decanted or filtered co-precipitate in solution. Separation may involve decanting or washing the filtered solid with a solution.

In one embodiment of the method of the first aspect, the co-precipitates (especially nickel, cobalt and manganese) can be washed after step (ii). This can dissolve and/or remove impurities present in the initially formed co-precipitate. Washing may be performed in at least one washing step (or at least two washing steps), such as at least one resuspension washing step. The initially formed co-precipitate may contain impurities due to association or adsorption, and washing may be necessary to remove these impurities even if they do not substantially precipitate. In one embodiment, washing may be performed using an aqueous solution (particularly a relatively pure aqueous solution such as distilled water) or using a solution (particularly an aqueous solution) comprising a base, acid or alkaline reagent (which may achieve the desired removal of impurity elements). can). The washing step may include multiple washing steps. The multiple washing steps may utilize different washing solutions. This can help remove various impurities. These washing solutions can remove contaminated solution entrained with the solids, remove impurities that have partially co-precipitated by reacting with the solids, or both.

In one embodiment of the method, the co-precipitate (or precipitated nickel, cobalt and manganese) may be mixed with lithium after step (ii). The lithium can then be calcined and co-precipitated (or nickel, cobalt and manganese). This can form cathode active material (CAM). The co-precipitate may provide NMC material for use as a cathode active material (CAM) in new batteries.

In one embodiment, the calcined lithiated co-precipitate has a lithiated co-precipitate greater than 10 mAh/g, or greater than 20, 50, 70, 100, 120, 130, 140, 150, 160, 170, 180, 190, 200 mAh/g. Battery performance can be provided. In this embodiment, electrochemical performance is defined as first cycle capacity as measured in a coin half-cell battery test conducted at a charge-discharge rate of 0.2C between a voltage range of 3.0-4.4V.

In another embodiment of the method of the first aspect, the remaining nickel and/or cobalt and/or manganese may be removed from the supernatant after step (ii) through precipitation and/or ion exchange.

The feed solution may include one or more impurities before or after the step of removing one or more impurities. These impurities include Ca ²⁺ , Mg ²⁺ , Li ⁺ , Na ⁺ , K ⁺ , NH ₄ ⁺ , S, F ^- and Cl ^- ; ^Cl- ; In particular, it may be selected from Ca ²⁺ , Mg ²⁺ , Li ⁺ , Na ⁺ , K ⁺ , S, F ^- and Cl ^- . Other impurities such as iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, zirconium and titanium may additionally or alternatively be present. Impurities may be at levels in the feed solution that, if included in the final co-precipitate, can negatively affect the performance of the CAM made therefrom.

In one implementation, the methods described herein include treating a feed solution comprising at least two metals selected from Ni, Co, and Mn, if desired, to remove some impurities and maintaining the required Ni:Mn:Co ratio (or Ni) in the solution. :Co, Ni:Mn or Co:Mn ratio), optionally mixing the resulting solution with a sufficient amount of another Ni and/or Co and/or Mn containing solution. The co-precipitate is selectively precipitated from solution in the presence of residual impurities, so that the filtered, washed and cleaned co-precipitate can be suitably pure with respect to impurities and have suitable properties such as sufficient performance as a battery material after further processing. there is.

In one implementation, precipitation of the co-precipitate is performed in the presence of some impurities. That is, some impurities present in the feed solution (or the solid materials used to produce the feed solution) may not be removed from that solution prior to the precipitation step. These impurities may not appear in the initially formed co-precipitate, or may appear in the initially formed co-precipitate but are later washed out or removed, or may be deposited in the final concentration and form to provide sufficient performance of the precursor material for its intended use as a battery cathode material. The amount of these impurities present in the co-precipitate can be controlled through control of the upstream impurity removal or separation step and control of the precipitation step and subsequent precursor washing and rinsing steps. In this context, “initially formed co-precipitate” herein means the material initially precipitated from the aqueous feed solution after pH adjustment, and “final co-precipitate” means any subsequent purification step described herein (e.g. , washing, drying) and should be understood to mean the solid material produced from the initially formed co-precipitate. The resulting co-precipitate can be used as a precursor material for lithium-ion battery manufacturing. In one implementation, the co-precipitate described herein is an initially formed co-precipitate.

The conventional or standard approach to the production of precursor materials starts with very high purity Ni or Co or Mn materials such as sulfates, metals, hydroxides, oxides, carbonates, etc., and dissolves these materials in a sulfate solution. Solutions of the three elements are then mixed together to achieve the required Ni:Co:Mn ratio. The resulting solution contains no or insignificant amounts of impurity elements. This NiMnCo solution can also be mixed with some ammonia-containing solutions, since ammonia can act as a complexing agent that can favorably mediate the precipitation reaction. The precursor is then precipitated using sodium hydroxide or sodium carbonate, or a combination of hydroxides and carbonates of sodium or ammonium. This results in the precipitation of mixed Ni/Co/Mn-containing oxides or carbonates or a mixture of oxides and carbonates. Afterwards, the precipitated material is filtered and washed with water. It is also sometimes washed or remixed with additional sodium carbonate solution which allows the remaining sulfate ions to be extracted. In this way, common precursor materials with adequate battery performance are produced from very high purity feed materials.

The main reason for this standard approach is that the production of battery precursor materials is believed to require very high purity feed materials to avoid contamination of the battery materials by any impurity elements that could negatively affect battery performance. .

However, the present inventors have surprisingly discovered that some elements can be present during the precursor manufacturing process without adversely affecting battery material performance. This means that it is possible to use feed materials and processes that introduce these elements into solution without contaminating or negatively affecting the precursor product. In some implementations, at least one impurity can be added to the aqueous feed solution prior to co-precipitation. This may be helpful in co-precipitation steps (e.g., when at least one impurity includes sodium and potassium salts).

Materials used to prepare the aqueous feed solution used in the process of the present invention may include those discussed in the co-pending application referenced above. It may also include one or more impurities, but may also include Ni or Co or Mn material that does not contain significant amounts of one or more of Ni or Co or Mn. In one implementation, at least one of the Ni, Co, or Mn materials may include at least one impurity. Therefore, the selective leaching conditions discussed for the co-pending application mentioned above also apply to the individual substances used here. These impurities need only be removed from the aqueous feed solution prior to the step of adjusting the pH to a concentration where sufficient performance as a battery material can be achieved by the final co-precipitate. The presence of some of these impurities may actually improve the performance of battery materials in some cases.

Alkali metals such as Li(I), Na(I), and K(I) are generally very soluble in acidic solutions and do not exhibit stabilization or oxidative precipitation behavior, making them soluble under the leaching conditions typically used to prepare aqueous feed solutions. will be. Alkaline earth metals such as Mg(II) generally exhibit similar behavior. Alkaline earth metals such as Ca(II) are also generally soluble, but may be limited to relatively low concentrations in sulfuric acid due to the solubility of various sulfate compounds. Therefore, these elements may be present in the feed solution. However, alkali metals such as Li, Na and K are generally soluble in aqueous solutions up to pH values greater than 12 and therefore do not generally precipitate or co-precipitate significantly. Alkaline earth metals such as Mg can precipitate as hydroxides or carbonates at about pH 8-9. Alkaline earth metals such as Ca can precipitate as carbonates at about pH 8-9 and as hydroxides at about pH 9-10. Therefore, during the co-precipitation step, the pH must be carefully controlled and variables such as base addition, initial concentration of the element in solution, and final concentration of the element in solution (and temperature, reagent addition rate, reagent concentration, and washing conditions) must be taken into account to determine the Other variables that may affect behavior must be carefully controlled. Then, select the precipitation reagent, carefully control the pH, and adjust the precipitation behavior to variables such as base addition, initial concentration of the element in solution, and final concentration of the element in solution (and temperature, reagent addition rate, reagent concentration, and washing conditions). other variables that may influence it), and the possible choice of precipitation reagent may control the behavior of these elements during the formation of the co-precipitate (or the final co-precipitate if multiple precipitation steps and/or multiple washing steps are used). You can. Although Li, Na and K are soluble up to pH values higher than the pH values at which the co-precipitates are precipitated, if selective precipitation and washing are not performed these elements can substantially contaminate the solid product, especially co-precipitates. This is especially true if the amount of these elements in the supernatant after precipitation is higher than if the reagent was added only for the precipitation of the co-precipitation itself.

This means that any Ni-, or Co- or Mn-containing material that also contains significant Li, Na, K, Mg or Ca impurities can be used as the feed material for preparing the feed solution, and instead of removing these impurities, selective dissolution and impurity removal can be used. and/or separation steps may be used, and any negative effects of these elements on battery performance may be prevented by the methods described herein, which may include control of precursor precipitation, washing, and cleaning processes. .

Step (ii) of the method described herein may comprise, for example, one or more of sodium carbonate, sodium hydroxide, potassium carbonate, potassium hydroxide, lithium carbonate, lithium hydroxide, ammonia, ammonium carbonate and ammonium hydroxide using a precipitation reagent (e.g. (To adjust the pH of the feed solution).

Step (ii) of the method described herein may be performed for any suitable amount of time. For example, step (ii) can be performed for at least 1 hour, 2 hours, 4 hours, 8 hours, 16 hours, 24 hours, 36 hours or 48 hours.

Careful control of many other factors such as the concentration of Ni, Co and/or Mn in the feed solution, rate of addition of Ni, Co and Mn solutions, rate of pH adjustment, temperature, reaction time, maturation time and presence of complexing ions such as ammonia is required. It can be used to produce an initial co-precipitate by performing precipitation of the precursor material at a target ratio of Ni:Mn:Co, which can then be filtered and washed to obtain a battery precursor material with sufficient performance. After the initial co-precipitate is formed, the environment in which the at least two metals are present can be adjusted to minimize or improve oxidation of the at least two metals, or to maximize oxidation of the at least two metals. Such control may include controlling the atmosphere surrounding the at least two metals or co-precipitates, or the initial or final co-precipitate. Controlling the atmosphere may include controlling the oxygen concentration or any gas phase in the atmosphere, the pressure or any gas phase of the atmosphere.

For suitable co-precipitate cathode active materials (precursors) in hydroxide form, it has been believed that the amount of nickel, manganese and/or cobalt in the co-precipitate should preferably be at least about 60% of the material on a dry solid basis. The remaining approximately 40% may be oxides, hydroxides or carbonates. In this 60% of the material, impurity limits for anionic species such as SO ₄ ^2- , F ^- and Cl ^- (but excluding the oxides, hydroxides or carbonates mentioned above) are typically 3000-4000 ppm; 300 ppm for alkali and alkaline earth metals (except lithium) (or alkaline earth metals); For metals and metalloids, it is specified as 50 ppm. Therefore, anions (especially excluding hydroxides, oxides and carbonates) may have a molar ratio (or mass ratio) of NMC to impurity of about 200:1. At 300 ppm, Ca and Mg (or Ca, Mg, Na, and K) have an NMC to impurity molar ratio (or mass ratio) of about 2000:1 in the solid, for example, at 50 ppm Fe has an NMC to impurity molar ratio of about 12,000:1. (or mass ratio) is provided.

The total amount of nickel, manganese and/or cobalt in the aqueous feed solution is at least 1 g/L, or at least 5 g/L, or at least 8 g/L, or at least 10 g/L, or at least 15 g/L, or at least 20 g/L, or It can be at least 30 g/L, or at least 50 g/L, or at least 70 g/L, or at least 90 g/L, or at least 120 g/L, or at least 150 g/L, or at least 200 g/L.

In one implementation, the amount of at least two metals in the co-precipitate is controlled to be less than 100% of the at least two metals in the aqueous feed solution. In one embodiment, the amount of at least two metals in the co-precipitate is less than 99%, less than 95%, less than 90%, less than 80%, or less than 70%, or less than 50% of the at least two metals in the aqueous feed solution. Or controlled to less than 20%. The amounts of nickel, manganese and cobalt in the co-precipitate relative to the amounts in the aqueous feed solution may be different percentages or may be the same.

In one embodiment, the supernatant of step (ii) comprises less than 1 mg/L, more than 1 mg/L, or more than 5, 10, 100, 200, 500 or 1000 mg/L of Ni, Co or Mn.

In one implementation, the concentration of an alkali metal (e.g., Na, Li, K) (or at least one alkali metal) in the aqueous feed solution is 100,000 ppm or less, or 80,000 ppm or less, or 60,000 ppm or less, or 50,000 ppm. or less than or equal to 40,000 ppm, or less than or equal to 30,000 ppm, or less than or equal to 20,000 ppm, or less than or equal to 15,000 ppm, or less than or equal to 10,000 ppm, or less than or equal to 7,000 ppm, or less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, or less than or equal to 3,000 ppm, or less than or equal to 2,500 ppm. or less, or 2,000 ppm or less. In other embodiments, the molar ratio of at least two metals to an alkali metal impurity (or at least one alkali metal impurity) in the aqueous feed solution is greater than about 1:50, or greater than about 1:10, or greater than about 1:5, or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about 120 :1, or greater than about 150:1, or greater than about 180:1, or greater than about 200:1. In other embodiments, the molar ratio of at least two metals to an alkali metal impurity (or at least one alkali metal impurity) in the aqueous feed solution is less than about 1:1, or less than about 5:1, or less than about 10:1, or Less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200: It may be less than 1. In another embodiment, the molar ratio of at least two metals to an alkali metal impurity (or at least one alkali metal impurity) in the aqueous feed solution is from about 1:10 to 23,000:1, or from about 1:10 to 100,000,000:1, or about 1. :10 to 300,000,000:1. In another embodiment, the molar ratio of at least two metals to an alkali metal impurity (or at least one alkali metal impurity) in the aqueous feed solution is from about 1:50 to 23,000:1, or from about 1:50 to 100,000,000:1, or about 1. :50 to 300,000,000:1. In one implementation, the alkali metal impurities do not originate from the precipitant.

In one embodiment, the percentage of alkali metal present in the aqueous feed solution that results in co-precipitation is less than 100%, or less than 99%, or less than 90%, or less than 50%, or less than 20%, or less than 1%.

In other embodiments, the co-precipitate comprises less than 10 ppm, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 20000 ppm of alkali metal in the dry solid. .

In one embodiment, the concentration of anionic impurities (such as F ^- and Cl ^- , but specifically excluding the oxides, hydroxides, sulfates or carbonates mentioned above) (or at least one anionic species impurity) in the aqueous feed solution is less than or equal to 100,000 ppm. , or 80,000 ppm or less, or 60,000 ppm or less, or 50,000 ppm or less, or 40,000 ppm or less, or 30,000 ppm or less, or 20,000 ppm or less, or 10,000 ppm or less, or 5,000 ppm or less, or 4,000 ppm or less, especially 3,000 ppm or less. , or 2,500 ppm or less, or 2,000 ppm. In other embodiments, the molar ratio of at least two metals to an anionic species impurity (or at least one anionic species impurity) in the aqueous feed solution is greater than about 1:10, or greater than about 1:5, or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about 120:1, or greater than about 150 :1, or greater than about 180:1, or greater than about 200:1. In other embodiments, the molar ratio of at least two metals to an anionic species impurity (or at least one anionic species impurity) in the aqueous feed solution is less than about 5:1, or less than about 10:1, or less than about 20:1, or It may be less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200:1.

In one embodiment, the percentage of anionic species present in the aqueous feed solution that results in co-precipitation is less than 100%, or less than 99%, or less than 90%, or less than 50%, or less than 20%, or less than 1%.

In other embodiments, the co-precipitate contains less than 10 ppm, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or Includes less than 5000 ppm, or less than 20000 ppm.

Without wishing to be bound by theory, the present inventors believe that due to phenomena such as liquid entrainment and atomic substitution, some anions (particularly F ^- , PO ₄ ^3- Cl ^- , SO ₄ ^{2 -} and NO ₃ ^- ) after performing physical separation. , it is believed that it may be present in the co-precipitate or supernatant. The inventors have advantageously discovered that these anionic impurities can be greatly controlled using the specified method. These anions can be removed to the required extent by washing or re-slurrying the co-precipitate or reacting with the washing or re-slurry solution.

In other embodiments, the concentration of alkaline earth metal impurities (e.g., Ca and Mg) (or at least one alkaline earth metal impurity) in the aqueous feed solution is less than 900,000 ppm, or less than 700,000 ppm, or less than 500,000 ppm, or 200,000 ppm. less than, or less than 100,000 ppm, or less than 50,000 ppm, or less than 40,000 ppm, or less than 30,000 ppm, or less than 20,000 ppm, or less than 10,000 ppm, or less than 5,000, or less than 1,000 ppm, or less than 800 ppm, or less than 600 ppm , or less than 500 ppm, or less than 400 ppm, or less than 300 ppm, or less than 250 ppm, or less than 200 ppm, or less than 150 ppm, or less than 100 ppm, or less than 50 ppm, or less than 20 ppm, or less than 10 ppm. , or less than 5 ppm, or less than 1 ppm, or less than 100 ppb, or less than 10 ppb. In a further embodiment, the concentration of alkaline earth metal impurities (such as Ca and Mg) (or at least one alkaline earth metal impurity) in the aqueous feed solution is greater than 900,000 ppm, or greater than 700,000 ppm, or greater than 500,000 ppm, or greater than 200,000 ppm, or greater than 100,000 ppm. greater than 50,000 ppm, or greater than 40,000 ppm, or greater than 30,000 ppm, or greater than 20,000 ppm, or greater than 10,000 ppm, or greater than 5,000 ppm, or greater than 1,000 ppm, or greater than 800 ppm, or greater than 600 ppm, or greater than 500 ppm greater than 400 ppm, or greater than 300 ppm, or greater than 250 ppm, or greater than 200 ppm, or greater than 150 ppm, or greater than 100 ppm, or greater than 50 ppm, or greater than 20 ppm, or greater than 10 ppm, or 5 greater than ppm, or greater than 1 ppm, or greater than 100 ppb, or greater than 10 ppb. In a further embodiment, the molar ratio of at least two metals to alkaline earth metal impurities (or at least one alkaline earth metal impurity) in the aqueous feed solution is greater than about 1:50, or greater than about 1:20, or greater than about 1:10, or about greater than 1:1, or greater than about 10:1, or greater than about 50:1, or greater than about 100:1, or greater than about 200:1, or greater than 500:1, or greater than about 1000:1, or greater than about 1500:1. greater than, or greater than about 2000:1, or greater than about 5,000:1, or greater than about 10,000:1. In one implementation, the molar ratio of at least two metals to alkaline earth metal impurities (or at least one alkaline earth metal impurity) in the aqueous feed solution is from about 300,000,000:1 to about 1:10; or greater than about 1:10, or greater than 1:1. In one embodiment, the molar ratio of at least two metals to alkaline earth metal impurities (or at least one alkaline earth metal impurity) in the aqueous feed solution is less than 1:50, or less than 1:20, or less than 1:10, or 1:5. or less than 1:1, or less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or Less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200:1, or less than about 500:1, or less than about 1000:1, or less than about 2000:1, or about Less than 5000:1, or less than about 10,000:1. In one embodiment, the ratio (by weight) of at least two metals:alkaline earth metals in the aqueous feed solution is less than 10,000:1. In one embodiment, the ratio (by weight) of at least two metals:calcium in the aqueous feed solution is less than 10,000:1. In a further embodiment, the ratio (by weight) of at least two metals:magnesium in the aqueous feed solution is less than 10,000:1. In one implementation, the ratio (by weight) of at least two metals in the aqueous feed solution: metals other than nickel, cobalt, manganese and alkaline earth metals and/or alkali metals is less than 6,000:1.

In one embodiment, the percentage of alkaline earth metal species present in the aqueous feed solution that is reported as co-precipitate is less than 100%, or less than 99%, or less than 90%, or less than 70%, or less than 50%, or less than 10%. or less than 1%, or less than 0.5%, or less than 0.1%.

In other implementations, the co-precipitate comprises less than 10 ppm, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 10000 ppm of alkaline earth metals in the dry solids.

In a further embodiment, the concentration of metal and metalloid impurities (or at least one metal or metalloid impurity) in the aqueous feed solution is less than 250 ppm, especially less than 50 ppm. In a further embodiment, the concentration of metal and metalloid impurities (or at least one metal or metalloid impurity) in the aqueous feed solution is greater than 1 ppb, especially greater than 100 ppb, or greater than 1 mg/L, or greater than 5 mg/L, or greater than 10 mg/L, or greater than 20 mg/L, or greater than 50 mg/L. Exemplary metal and metalloid impurities may be selected from the group consisting of iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, zirconium, scandium and titanium, among others. In one implementation, the molar ratio of at least two metals to metal and metalloid impurities (or at least one metal or metalloid impurity) is less than 50:1, or less than 100:1, or less than 500:1, or 1,000:1. less than, or less than 5,000:1, or less than 10,000:1, or less than 20,000:1, or less than 40,000:1, or less than 60,000:1, or less than 80,000:1, or less than 100,000:1, or less than 500,000:1. In one implementation, the molar ratio of the at least two metals to Fe impurities is from about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one implementation, the molar ratio of the at least two metal to Fe impurities is less than 10,000:1, or less than 20,000:1, or less than 100,000:1, or less than 500,000:1, or less than 1,000,000:1. In one implementation, the molar ratio of the at least two metals to Al impurities is from about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one implementation, the molar ratio of the at least two metals to Al impurities is less than 10,000:1, or less than 20,000:1, or less than 100,000:1.

In one implementation, the ratio (by weight) of metal:iron in the aqueous feed solution is less than 16,000:1. In one implementation, the ratio (by weight) of at least two metals:copper in the aqueous feed solution is less than 6,000:1. In one implementation, the ratio (by weight) of at least two metals:aluminum in the aqueous feed solution is less than 10,000:1. In one implementation, the ratio (by weight) of at least two metals:niobium in the aqueous feed solution is less than 500,000:1. In one implementation, the ratio (by weight) of the at least two metals:tungsten in the aqueous feed solution is less than 500,000:1. In one implementation, the ratio (by weight) of at least two metals:zirconium in the aqueous feed solution is less than 500,000:1.

In one embodiment the percentage of metal and metalloid species present in the aqueous feed solution that results in co-precipitation is less than 90%, or less than 10%, or less than 1%.

In another embodiment, the co-precipitate contains less than 10 ppm, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 10,000 ppm of metal and metalloid species in the dry solid. Includes less than

However, the inventors have found that the above specifications can be somewhat arbitrary in some cases. For example, up to 500 or 1000 ppm of Ca and Mg in the final co-precipitate do not seem to have a significant effect on battery material performance. Therefore, lower proportions may be acceptable for these elements. It is considered that calcium levels of up to 1000:1 of at least two metals: Ca can be present in the co-precipitate without negative effects.

As explained elsewhere herein, when producing the final co-precipitate using the method of the present invention, it is possible to largely avoid precipitation of many of these elements, while for other elements there may be some degree of co-precipitate. is relatively difficult to avoid. However, in the latter case, co-precipitation of impurities may have little effect on the performance of the final co-precipitate or may provide acceptable performance of the final co-precipitate when used as a battery material.

Using Mg as an example, it was possible to achieve Mg co-precipitation of 100%, near 100%, less than 100%, less than 50%, substantially less than 10%. Assuming 1% precipitation of Mg from solution and precipitation of Ni, Co, and Mn, if the ratio of at least two metals:Mg in the feed solution is 10:1, then the ratio of at least two metals:Mg in the feed solution is 1000:1. This can be achieved.

We have discovered that much smaller Mg co-precipitation is possible and have demonstrated that a feed solution containing 1:17 of both metals:Mg is feasible to produce acceptable co-precipitation. Accordingly, feed solutions containing at least two metals:Mg at 1:10 or even 1:50 may provide acceptable co-precipitates at the desired Mg ratio. Feed solutions containing at least two metals: Mg in ratios of up to 1:1 or even 1:10 may provide acceptable co-precipitates. Similar ratios are likely to be achieved for Ca.

For other elements, such as Fe, co-precipitation may be 100%, near 100%, or less than 100%. 100% co-precipitation of Fe and 100% precipitation of at least two metals with an initial co-precipitation ratio of at least two metals:Fe of 12,000:1 (which is approximately equivalent to the target concentration of 50 ppm for the final co-precipitate) To achieve this, a ratio of at least two metals:Fe in solution of 12000:1 would be the upper limit. In this case, the method may still allow for treating this aqueous feed solution to produce a co-precipitate. However, if less than 100% Fe is co-precipitated, the ratio of Fe to at least two metals in the aqueous feed solution can be less than 12,000:1, and less than 50 ppm Fe in the co-precipitate can be achieved. More than 50 ppm of Fe or other elements may be tolerated in the final co-precipitate without significantly affecting battery material performance.

Conversely, it is unlikely that a feed solution free of impurities is readily available or could be used in the present invention. The practical minimum value of each impurity or combined impurities present is about 2 ppb, about 3, 5, 10, 50, 100, 200 or 500 ppb, or about 1, 2, 5, 10, 50, 100, 200, 500, It may be 1000, 2000, 5000 or 10000 ppm.

In one implementation, the amount of the at least one impurity for the at least two metals in the co-precipitate is less than the amount of the at least one impurity for the at least two metals in the aqueous feed solution. In one embodiment, the co-precipitate contains less than 100% of the at least one impurity in the aqueous feed solution, particularly 90%, or 80%, or 70%, or 60%, or 50% of the at least one impurity in the aqueous feed solution. , or 40%, or 30%, or 20%, or 10%. In one embodiment, the co-precipitate contains less than 100% of the alkali metal and anion in the aqueous feed solution, particularly 90%, or 80%, or 70%, or 60%, or 50% of the alkali metal and anion in the aqueous feed solution. , or 40%, or 30%, or 20%, or 10%. In one embodiment, the co-precipitate contains less than 100% of the alkaline earth metals in the aqueous feed solution, especially less than 90%, or 80%, or 70%, or 60%, or 50%, or 40% of the alkaline earth metals in the aqueous feed solution. %, or 30% or 20% or less than 10%. In one implementation, the co-precipitate comprises less than 100% of the alkali metal and ionic species in the aqueous feed solution; The supernatant comprises at least 0.1% of alkaline earth metals, less than 100% of alkali metals and ionic species in the aqueous feed solution, and less than 100% of metals other than the alkali and alkaline earth metals in the aqueous feed solution.

In one embodiment, at least 1% and up to 100% of the nickel, cobalt and/or manganese are from impure sources (the ratio of nickel, cobalt and/or manganese:impurities is less than 0.01:1, less than 0.1:1, 1:1). Less than 1, less than 10:1, less than 100:1, less than 500:1, less than 1000:1, less than 5000:1, less than 10,000: less than 1, less than 50,000:1, less than 200,00:1 or less than 500,000:1 ) is derived from.

The inventors have advantageously discovered that by treating the impure solution, the level of beneficial impurities can be controlled in the final product. In prior art processes, such beneficial impurities (such as Mg or Al) can be added separately as dopants. Using the method of the present invention, these costs can be avoided while still producing acceptable co-precipitates. This allows for a variety of feed materials to be used in the method. This is also particularly important for some specific feed materials containing impurities, such as aluminum and magnesium, which can also be used as dopants; Alternatively, if recycled battery feed materials are used, these recycled materials may contain impurities that can also be used as dopants, and the method described allows these impurities present in the feed materials to be absorbed into the supernatant and co-precipitate at the desired concentrations. The way it is reported can be controlled. In all of these cases, a significant portion of the desired dopant elements may originate from a feed material comprising at least one metal and at least one impurity.

As previously discussed, a typical previous process involved dissolving highly purified individual nickel, cobalt and manganese sulfate feed materials into a solution at specific ratios and purities and then performing co-precipitation from that solution. In such processes, such salt feed material may have impurities of, for example, 5 ppm or less. Two examples of specifications required to use nickel sulfate hexahydrate salt in the manufacture of NMC materials are provided in the table below. Considering the very low allowable impurity concentrations of these salts for NMC material production, the solution used for NMC precipitation will have an equally low NMC:impurity ratio as shown in the second table. Avoiding the cost of purifying the feed material to very low impurity concentrations is a major advantage of the present invention, as it allows the production of NMCs containing more impurities without the need to perform expensive steps to remove impurities from the solution. This is because NMC materials can be produced from materials.

In some prior art documents, the feed material used to prepare the solution for NMC co-precipitation is a battery cathode that contains NMC-like materials or at least one of the elements Ni, Co and Mn, as well as may contain some impurity elements. A substance that has been or could have been used previously. In such cases, very few impurities may be present in the feed material, or the impurities present in the feed material are at such low concentrations that the material is equivalent to a standard highly purified feed material. In such cases, co-precipitation can occur under non-selective conditions.

The feed material (or feed mixture of Step A) for use in the process may include recycled material, ore products, intermediate ore products, and/or NMC salts containing impurities.

Recycled materials may include, but are not limited to, used lithium-ion batteries (black mass) and used catalysts containing nickel, cobalt and/or manganese. The recycled material may contain at least one of Co/Mn/Ni and at least one impurity. Many prior art processes fail to take into account the presence of the following impurities in the black mass: Zn, Cr, W, P, Ti, S, Pb, K, Mo, Nb, Ba, Cd, V, Rb, Y, Zr, Pt, Sb, Sc, Si and/or Sn. These impurities can be substantially or completely removed from the co-precipitate formed by the method of the present application. In some cases, some recycled materials may contain some impurity elements due to contamination or changes in the initial lithium-ion battery composition.

Ore and ore intermediates containing one or more of nickel, cobalt and manganese can be leached to create an aqueous feed solution suitable for co-precipitation. These feeds may inherently contain impurities and may include laterites and sulfides (and their suspended concentrates) as well as more processed feeds such as MHP and MSP. To the knowledge of the inventors, the creation of co-precipitates from these feed materials containing impurities of the types and concentrations present in these ores and ore intermediate products has not been contemplated in the prior art.

NMC salts containing impurities may be, for example, a combination of pure Co and Mn salts with Ni salts containing at least one impurity, or other combinations of pure salts and impurity salts.

In one embodiment, step (ii) comprises at least two of performing the co-precipitation at a lower pH, changing the method of base administration, changing the type of base, adding a precipitant, or an aqueous feed solution. It may include the step of adjusting the concentration of the metal. These steps can help control the selectivity of co-precipitation. For example, carbonate bases (eg, sodium carbonate) may be less suitable for aqueous feed solutions containing high concentrations of Ca due to the formation of stable CaCO ₃ . In this case, a hydroxide base can improve selectivity. Methods of base administration may include continuous, semi-continuous, semi-batch or batch administration, or combinations thereof. The method of the present invention can also help control the physical properties of the co-precipitate. These physical properties may include particle size, bulk density, tapped density, shape, shape, and crystallinity.

In one implementation, the co-precipitation step (step (ii)) may include adding a precipitant to the feed solution. Precipitating agents may be oxidizing agents, bases or organic anionic compounds. Oxidizing and reducing agents may be as defined elsewhere herein. Organic anionic compounds may include oxalates. The precipitant may be added in a stoichiometric amount relative to the at least two metals (e.g., at least 1, 1.5, 2, 2.5 or 3 equivalents of precipitant). The precipitant may be added in a substoichiometric amount (e.g., less than 1, 0.9, 0.8, 0.7 or 0.6 equivalents of precipitant) for the at least two metals. Using substoichiometric amounts of precipitant can result in less than 100% recovery of at least two metals from the feed solution.

After the co-precipitation step (step (ii)), the method may further comprise mixing with lithium. This may include calcination. Through these steps, cathode active material (CAM) can be produced.

feed solution to effect oxidation of one or more of Mn, Co and Ni, in order to adjust or achieve a certain ratio of these elements in the solid prior to step (ii) and to further increase the selectivity of these elements over the impurity elements during the co-precipitation step. It is also possible to control oxidation by adding an oxidizing agent (which may include controlling or adding an oxidizing agent in gaseous form).

Once the co-precipitate is formed, it can be separated by any suitable means to separate it. This includes sedimentation, centrifugation, filtration, decantation and combinations thereof. The method may include decanting and/or filtration to separate the co-sedimentate. The separated co-precipitate can then be washed. It can be cleaned with an appropriate cleaning agent to remove unnecessary impurities. Suitable washes are alkaline, water, acid or ammonia washes. The pH of the alkaline wash may be greater than about 9, or greater than about 10, 11, or 12.

Optionally, after washing, the co-precipitate may be supplemented with lithium. Accordingly, the method may include adding lithium to the co-precipitate. Lithium may be in the form of lithium hydroxide or lithium carbonate, for example. This may take the form of physically mixing the co-precipitate with lithium. Lithium may be added in a molar ratio to the sum of Ni, Co and Mn greater than about 1:1.

The co-precipitate can be dried. This may be any suitable temperature, from about 80 to about 150° C., or from about 80 to 100, 100 to 150, 100 to 130, 130 to 150 or 90 to 120° C., for example about 80, 90, 100, 110, 120, It can be dried at 130, 140 or 150°C. This may be accomplished by passing air or other gas through the co-precipitate at a specified temperature, or may involve allowing the co-precipitate to rest at that temperature. Drying time may be sufficient to achieve moisture levels of less than about 10%, or less than about 5, 2, 1, 0.5, 0.2 or 0.1% by weight. This means at least about 5 hours, or at least about 6, 7, 8, 9 or 10 hours, or about 5 to about 20 hours, or about 5 to 15, 5 to 10, 10 to 15, 15 to 20 hours, or 7 to 12 hours. It may be an hour, for example about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 hours.

In one implementation, steps (i) and (ii) of the method of the first aspect may be repeated. That is, the method may include:

(i) providing an aqueous feed solution comprising the at least one metal (or at least two metals) and at least one impurity; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, to (a) a ball comprising said at least one metal (or at least two metals) - precipitate; and (b) providing a supernatant containing the at least one impurity;

(iii) separating the co-precipitate from the supernatant;

(iv) dissolving the co-precipitate in solution to provide a solution in which at least one metal (or at least two metals) is at least partially dissolved; and

(v) adjusting the pH of the solution of step (iv) to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, so that (a) said at least one metal (or at least two metals) co-precipitates comprising; and (b) providing a supernatant containing the at least one impurity.

In one implementation, step (iv) may include dissolving the co-precipitate in an acidic solution. The characteristics of step (v) may be the same as described above for step (ii). This method advantageously allows easier separation of impurities. For example, the pH of the solution in step (v) may be higher than the pH of the solution in step (ii).

In one implementation, the method further includes producing a lithium ion battery using the co-precipitate.

According to a second aspect of the invention, a method is provided for producing a precipitate comprising at least one metal selected from nickel, cobalt and manganese, the method comprising:

(i) providing an aqueous feed solution comprising the at least one metal; and

(ii) precipitating said at least one metal from the feed solution by adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2.

The aqueous feed may contain at least one impurity. Accordingly, adjusting the pH of the feed solution may provide a supernatant containing the at least one impurity. Accordingly, in one implementation of the second aspect there is provided a method of producing a precipitate, wherein the precipitate comprises at least one metal selected from nickel, cobalt and manganese, the method comprising:

(i) providing an aqueous feed solution comprising the at least one metal and at least one impurity; and

(ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, thereby producing (a) a precipitate comprising said at least one metal; and (b) providing a supernatant containing the at least one impurity.

The features of the second side may be the same as those described above for the first side. Where the context permits, a reference to “at least two metals” in a first aspect may be a reference to “at least one metal” in a second aspect. Similarly, where the context permits, a reference to “co-precipitate” in a first aspect may be a reference to “precipitate” in a second aspect.

In a third aspect, there is provided a co-precipitate (or precipitate) comprising at least two metals selected from nickel, cobalt and manganese, the co-precipitate (or precipitate) produced by the method of the first or second aspect. do.

The present invention relates to the formation of co-precipitates comprising nickel, manganese and/or cobalt suitable for use as precursor materials for producing lithium ion batteries. Mixtures of Ni, Co and/or Mn containing materials containing some level of impurities can be selectively dissolved, at least partially, using, for example, the processes described in this application. The resulting solution may be treated, if necessary, to remove some impurities and mixed with a sufficient amount of one or more other Ni and/or Co and/or Mn containing solutions to achieve the required Ni:Mn:Co ratio. . Co-precipitates are then selectively formed in the solution, if any remaining impurities are present, so that the filtered, washed and cleaned product is suitably pure with respect to impurities and has the appropriate properties to achieve sufficient performance as a battery material after further processing. .

In one embodiment, the co-precipitate contains less than about 1000 ppm iron, or less than 500 ppm iron, or less than 200 ppm iron, or less than 100 ppm iron, or less than 50 ppm iron, or about 40 ppm iron, or less than about 20 ppm iron, or less than about 10 ppm iron, or less than about 5 ppm iron, or less than about 2.5 ppm iron, or less than about 1 ppm iron. In other embodiments, the co-precipitate has less than 50,000 ppm, or less than 20,000 ppm, less than 10,000 ppm, less than 5,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, Contains less than 10 ppm or less than 5 ppm magnesium. In other embodiments, the co-precipitate has less than 50,000 ppm, or less than 20,000 ppm, less than 10,000 ppm, less than 5,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, Contains less than 10 ppm or less than 5 ppm calcium. In other embodiments, the co-precipitate has less than 50,000 ppm, or less than 20,000 ppm, less than 10,000 ppm, less than 5,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, Contains less than 10 ppm or less than 5 ppm of alkaline earth metals. In other embodiments, the co-precipitate has less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm alkali. Contains metal. In other embodiments, the co-precipitate has less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm alkali. and metals other than alkaline earth metals. In other embodiments, the co-precipitate has a concentration of less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm. Contains metal. In other embodiments, the co-precipitate has less than 10,000 ppm, less than 5,000 ppm, less than 3,000 ppm, less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, 20 Contains less than 10 ppm, less than 10 ppm, or less than 5 ppm of anionic species other than hydroxide or carbonate.

In a fourth aspect, the invention provides use of the co-precipitate of the third aspect for producing lithium-ion batteries.

The features of the third and fourth aspects of the invention may be the same as those described for the first aspect of the invention.

According to a fifth aspect of the invention, there is provided a method for producing leachate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising the following steps:

A. Providing a feed mixture comprising at least two metals, the feed mixture being one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:

The oxidized feed has more of at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2;

The reduced feed has more of the at least two metals in the less than 2 oxidation state than in the greater than 2 oxidation state, or has substantially all of the at least two metals in the 2 oxidation state and at least some of the at least two metals in sulfide form. have; and

The unoxidized feed has substantially all of the at least two metals in the oxidation state of 2 and substantially none of the at least two metals in the sulfide form;

B. Treating the feed mixture with an aqueous solution to form a leachate comprising said at least two metals, wherein the pH of the aqueous solution is such that the pH of the leachate is from about -1 to about 7 (or about -1 to about 6, or about 1 to about 7, or about 1 to about 6, and where:

If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and

If the feed mixture is a reduced feed, the treatment further comprises adding a reagent comprising an oxidizing agent;

The leachate thus contains at least two metals in an oxidation state of 2.

The features of the fifth aspect of the invention may be the same as those described for the first or second aspects of the invention.

According to a sixth aspect of the invention, there is provided a method of producing leachate comprising two metals selected from nickel, cobalt and manganese, wherein the leachate has a pH of about 1 to about 7 (or about 1 to about 6). ), contacting a mixture comprising at least two metals with an aqueous solution at a pH of ) to provide a leachate comprising the at least two metals in solution; At least some of the two metals in the feed mixture have an oxidation state of 2.

The method of the sixth aspect may include treating the mixture with a reducing agent. In one implementation, at least a portion of the nickel, cobalt, and/or manganese may be in an oxidized state, and the treatment may reduce at least a portion of the oxidized nickel, cobalt, and/or manganese. It will be noted that this embodiment is similar to the fifth aspect of the invention. In one implementation, the method of the sixth aspect may include removing one or more impurities from the leachate.

The features of the sixth aspect of the invention may be the same as those described for the fifth aspect of the invention.

In a seventh aspect, the invention provides a leachate comprising at least two metals selected from nickel, cobalt and manganese, optionally all three metals, said leachate produced by the method of the fifth aspect.

In an eighth aspect, the invention provides a leachate comprising at least two metals selected from nickel, cobalt and manganese, optionally all three metals, said leachate produced by the method of the sixth aspect.

Any of the features described herein may be combined in any combination with one or more of the other features described herein within the scope of the invention.

In one implementation, the present disclosure relates to the dissolution of certain metals, particularly two or three of nickel, cobalt and manganese. Dissolution may be performed in an at least partially selective manner. This is between about 1 and about 7, or about Using control of the final pH between 1 and about 6 and control of the oxidation and reduction reactions, it is possible to create a solution with approximately the correct proportions for precipitation of battery precursor materials. The process can then remove and/or separate some impurities from the resulting solution so that the resulting solution can be used in the production of battery precursor materials. Depending on the initial solid material, a reducing agent, an oxidizing agent, both, or neither may be used. The material does not necessarily need to contain all of the Ni, Mn, and Co, nor does it need to contain all of the Ni, Mn, and Co needed for the final product. This process is intended to produce a solution for use in the production of precursor materials.

One aspect of the process is that a significant portion of the selected metal is kept together through the leaching and impurity removal or separation steps so that the ratio of Ni:Mn:Co in the resulting leachate can be adjusted and used for precipitation of NMC type materials.

In one embodiment, the feed mixture for the process comprises residues from the SAL process, products of the process, materials from batteries, nickel oxide ores, as long as these materials contain significant amounts of at least two of Ni, Co, and Mn. Other oxide materials, such as intermediate nickel products such as mixed hydroxide precipitates (MHP), mixed carbonate precipitates (MCP) or mixed sulfide precipitates (MSP), nickel sulfide ores, nickel sulfide concentrates or nickel sulfide mats; Alternatively, it may contain a metallic material.

These materials can generally be classified according to the oxidation state of Ni, Co, and Mn they contain. Nickel and cobalt often exist in metallic forms that can be referred to as Ni(0) or Co(0). They can be oxidized to the ionic form Ni(II) or Ni(III), Co(II) or Co(III). Mn may exist in the forms Mn(0), Mn(II), Mn(III), Mn(IV), and Mn(VII). Other oxidation states of these elements may also exist but are less common. To dissolve these metals in a relatively selective manner, inventors found it convenient to change the oxidation state of the elements to the (II) state. Therefore, any material with states of Ni, Co, and Mn higher than (II) is considered oxidized relative to the desired (II) form, and any material with oxidation states lower than (II) is considered oxidized relative to the desired (II) form. It is considered reduced compared to The reason for obtaining these elements in state (II) is that in that form all three metals are quite soluble in acidic solutions of sulfuric, nitric or hydrochloric acid between a pH of about 1 and a maximum of about pH 6 or 7. For Mn, (III) or (IV) is only significantly soluble in acidic solutions below about pH 3. Therefore, if an element in the (II) state is obtained, it can be dissolved even under less acidic conditions. This provides selectivity for many impurities.

The residue from the SAL process has most of the Ni as Ni(II), most of the Co as solids in the form of Co(III) or mixed Co(II)/Co(III), and most of the Mn as Mn(III). or Mn(IV). This can be classified as an oxidized feed. In battery cathode materials, most of the Ni is Ni(III), most of the Co is Co(III), and most of the Mn is Mn(III) and Mn(IV). This can be classified as an oxidized feed. Nickel oxide ores can have Ni as Ni(II) or Ni(III), Co as Co(II) or Co(III), and Mn as Mn(II), Mn(III), and Mn(IV). . This can be classified as an oxidized feed. The MHP and MCP intermediates contain most of the Ni as Ni(II), most of the Co as Co(II), and most of the Mn as Mn(II). It is classified as a non-oxidized feed.

MSP and other sulfide materials have most of their Ni as Ni(II) and most of their Co as Co(II). In general, there is little Mn associated with sulfides. Since Ni and Co in these sulfide materials are bound to sulfur, it is not necessary to oxidize or reduce Ni or Co to dissolve them, but it is necessary to oxidize the sulfur so that Ni and Co can be released from the sulfide form. Therefore, the sulfide source is classified as a reduced feed.

There may be minor oxide forms of these elements in the metal-related (II) state, but the metallic forms are mostly Ni(0) for Ni, mostly Co(0) for Co, and mostly Mn(0) for Mn. )am. It is therefore classified as reduced feed.

Generally, the oxidized feed must be reduced with a suitable reducing agent so that it can be dissolved to form leachate. Non-oxidized feeds do not require significant reducing or oxidizing agents to dissolve Ni, Co and/or Mn to form leachate. The reduced feed must be oxidized with a suitable oxidizing agent so that it can be dissolved to form leachate.

In one implementation, a feature of this approach is that in the oxidized feed, oxidized nickel will typically be the first element to be reduced, followed by oxidized cobalt, and then oxidized manganese. These three elements can be reduced to the desired +2 oxidation state and thus dissolved in a way that controls the amount of each element contributing to the leachate. Choosing a reducing agent or using a reducing agent followed by an oxidizing agent can also control the degree of dissolution of these metals.

Additionally, this behavior allows the reducing agent to reduce and dissolve significant amounts of Ni/Co/Mn metal before it consumes the reducing agent and/or reacts with significant amounts of other elements that may be dissolved by the reduction reaction. Fe is an example of an element that follows similar behavior to Ni and Co. That is, Fe can exist in the Fe(II) and Fe(III) states, and Fe(II) is significantly soluble in acids below about pH 7, but Fe(III) is only significantly soluble at pH below about 3. However, if the reduction is controlled by carefully controlling the reagent addition rate, addition amount, reagent selection, temperature, and other parameters, the reduction of Fe(III) to Fe(II) is achieved until most of Ni, Co, and Mn react to form the (II) form. ), the reduction can be stopped or minimized. Alternatively, Ni(II) reacts with Fe(II) rather than Co(II) or Mn(II) after reduction, or at least with Fe(II) before Ni(II) Co(II) and/or Mn(II). A reactive oxidizing agent can be added, which causes the Fe(II) to oxidize back to Fe(III) and return to the solid phase. Therefore, selective dissolution of Ni/Co/Mn in Ni/Co/Mn-containing materials but not Fe can be achieved. The optional dissolution step may be followed by a solid/liquid separation step, such as decanting, centrifugation, sedimentation and/or filtration.

This approach to controlling reduction and oxidation can also be applied to reduced materials such as sulfide and metal sources of Ni, Co, and Mn. Sulfide materials can react with oxidizing agents to oxidize the sulfide portion and dissolve Ni, Co, and Mn. The oxidizing agent and dissolution can be controlled so that the Ni, Co, and Mn portions of the material are oxidized and dissolved before other impurity portions of the material are oxidized and/or dissolved, producing a relatively clean solution containing Ni, Co, and Mn. The material or solution may also be further oxidized so that any impurity elements, such as Fe, are oxidized and precipitated before significant amounts of Mn, Co or Ni are oxidized and precipitated.

Similarly, metals can react with oxidizing agents (e.g. as described above), causing the contained Ni/Co/Mn moieties to oxidize to their (II) state and dissolve, and noble and platinum group metals such as Ni, Co and/or controlling the degree of oxidation to prevent dissolution of Mn metal or other metallic substances that subsequently oxidize after noble metals including copper, lead and tin. Additional oxidation can also be used to control the ratio of Ni:Co:Mn in solution by oxidizing and precipitating impurity metals such as Fe or even Mn.

The main leaching impurities commonly associated with these materials are alkali elements (main considerations are Li, Na, K), alkaline earth elements (main considerations are Mg, Ca), transition metals (main considerations are Sc, Ti, V, Cr, Fe, Cu, Zn, Cd), other metals (main considerations are Al, Sn, Pb) and metalloids (main considerations are Si, As, Sb).

Metals such as Li(I), Na(I) and K(I) are very soluble in acidic solutions and do not exhibit stabilization or oxidative precipitation behavior and are therefore generally soluble under the leaching conditions used in the process described herein. Mg(II) also shows similar behavior. Ca(II) is also generally soluble, but is limited to relatively low concentrations in sulfuric acid due to the solubility of various calcium sulfate compounds. Typically, these elements are soluble in solutions up to a higher pH of about 8 or 9, so this is not a major concern as they do not contaminate the battery precursor product as they remain in solution during subsequent precipitation processes used for Ni, Co, and/or Mn recovery. No.

For other important impurity elements, Fe dissolution can be controlled by the oxidation, reduction and pH behaviors discussed above. Sc(III), Ti(IV), V(V), Cr(III), Al(III), Sn(IV), As(III), Sb(III) and to some extent Cu(II), Zn( II) and Cd(II) can be controlled by the leaching pH, as these elements are significantly soluble at lower pH values and not significantly soluble at higher pH values in the pH range of about 1-7 or 1-6. Because it doesn't. Pb(II) is also generally soluble, but is limited by the solubility of various lead sulfate compounds in sulfuric acid. Si is generally not significantly soluble in the pH range of about 1-7 or 1-6.

Cr, Sn, As and Sb can all take on different oxidation states which affect their solubility. In general, higher oxidation states of these elements are more soluble, so the oxidation or reduction of these elements can be controlled to achieve the mentioned oxidation states, which in turn will achieve the desired selectivity of Ni/Co/Mn for these elements. will be.

As discussed above, the goal of the process described in one embodiment of the disclosure is to control oxidation and reduction reactions and solution pH to obtain Ni, Co and/or Mn in solution with minimal impurities.

Subsequent impurity removal steps such as pH adjustment, ion exchange, solvent extraction, precipitation and/or cementation reactions may be performed to remove and/or separate additional impurities from this solution. For example, Cu, Zn, and Cd can be removed from solution through various ion exchange or solvent extraction processes. Alternatively or additionally, any two or all of Ni, Co and Mn may be separated from impurities in the leachate by ion exchange or solvent extraction such that they remain together.

The proportions of the various substances used in the leaching process can be adjusted to target the desired ratio of Ni:Co:Mn in the final leachate.

Additional Ni, Co or Mn may be added to the leachate before or after the impurity removal step to adjust the Ni:Co:Mn ratio as needed.

In one implementation, the end goal may be a solution with the necessary Ni:Co:Mn ratio and sufficient purity so that battery negative electrode precursor material can be produced from that solution.

It should be noted that the term NMC refers to any material containing Ni, Co and Mn that can be used as an active material in batteries.

Preferred features, embodiments and variations of the invention can be identified from the following detailed description, which provides sufficient information to those skilled in the art to practice the invention. The detailed description should not be considered to limit the scope of the foregoing summary in any way.
Notwithstanding any other forms that may fall within the scope of the invention, preferred embodiments of the invention will now be described by way of example only with reference to the accompanying drawings:
1 shows a flow diagram of a method for producing a co-precipitate comprising nickel, manganese and cobalt obtained from solid residues according to a method comprising an embodiment of the invention.
Figure 2 shows a schematic diagram of a second method of producing a co-precipitate comprising nickel, manganese and cobalt according to a method comprising a second embodiment of the invention.
Figure 3 depicts the removal of unwanted metals from cobalt concentrate using an acid pre-wash step based on the volume of filtrate.
Figures 4A and 4B show recovery plots for solutions of various metals compared to pH during leaching of pre-cleaned cobalt concentrate under reducing conditions.
Figures 5a, 5b, and 5c show plots of the change in solution phase concentration of various metals during the process of completing the reduction reaction.
Figures 6a-6d show recovery plots for solutions of major elements as a function of reaction time and pH, where solids were treated at 2.5 hours with 5% initial solids and 100% stoichiometric SO ₂ addition at a reactor temperature of 55°C. It has been done. The solids used are as follows. Figure 6a: BMJ-A; Figure 6b: BMJ-B; Figure 6c: BMC; Figure 6d: BMK;
Figures 7a-7d show recovery plots for solutions of major elements as a function of reaction time and pH, where BMK solids were reacted at 5% initial solids and 100% stoichiometric at a reactor temperature of 55°C with acid addition under various conditions. Treated with SO ₂ addition. Acid was added as follows. Figure 7a - H ₂ SO ₄ was added stepwise to the sampling point to lower the pH to 4.5 and SO ₂ (31 mL/min) was added over 2.5 hours; Figure 7b - H ₂ SO ₄ was added continuously to provide 100% of the stoichiometric requirement (1 mL/min) in 200 minutes and SO ₂ (31 mL/min) was added over 2.5 hours; Figure 7c - H ₂ SO ₄ H was added continuously to provide 100% of the stoichiometric requirement (2.2 mL/min) in 1.5 hours and SO ₂ (52 mL/min) was added over 1.5 hours; Figure 7d - 100% of the stoichiometric requirement of H ₂ SO ₄ was delivered at the start of the reaction, and SO ₂ was added within 0.5 hours (220 mL/min). Figure 7e shows a comparative recovery plot for solutions of the main elements as a function of reaction time and pH, where BMK solids were recovered at 200 °C by continuous addition of H ₂ SO ₄ without 5% initial solids and SO ₂ at a reactor temperature of 55 °C. min to produce 100% of the stoichiometric requirement (1 mL/min).
Figure 8 shows a recovery plot for solutions of the major elements as a function of reaction time and pH, where BMK solids are 20% initial solids at a reactor temperature of 55°C and 100% stoichiometric addition of SO ₂ in 1.5 hours (290 mL/min) and continuous addition of 50% H ₂ SO ₄ provided 100% of the stoichiometric requirement (2.9 mL/min) in 1.5 hours.
Figures 9a and 9b show recovery plots for solutions of key elements as a function of reaction time and pH, where BMK solids were added at 5% initial solids at reactor temperature and 100% stoichiometric addition of SO ₂ in 1.5 hours (52 mL). /min) and 100% of the stoichiometric requirement (2.2 mL/min) was achieved within 1.5 hours by continuous addition of H ₂ SO ₄ . Reactor temperatures were as follows: Figure 9a - 75°C; Figure 9b - 35°C;
Figure 10 shows a flow diagram of a method of one implementation of the invention.
Figure 11 shows a flow diagram of a method of another embodiment of the present invention.
Figure 12 shows a graph of target metal precipitation versus pH at 75°C, 50 ml/min air using pH adjusted by automatic titration of 2.5M NaOH.
Figure 13 shows a graph of impurity element precipitation versus pH at 75°C, 50 ml/min air using pH adjusted by automatic titration of 2.5M NaOH.
Figure 14 shows a graph of target metal precipitation versus pH at 75°C, 50 ml/min air using pH adjusted by automatic titration of 200 g/l Na ₂ CO ₃ .
Figure 15 shows a graph of impurity element precipitation versus pH at 75° C., 50 ml/min air, using pH adjusted by automatic titration of 200 g/l Na ₂ CO ₃ .
Figure 16 shows a graph of target metal precipitation versus pH at 75°C, 50 ml/min air using pH initially adjusted by automatic titration of 200 g/l Na ₂ CO ₃ after addition of solid MnCO ₃ and BNC. do.
Figure 17 shows a graph of impurity element precipitation versus pH at 75°C, 50 ml/min air using pH initially adjusted by automatic titration of 200 g/l Na ₂ CO ₃ after addition of solid MnCO ₃ and BNC. do.
Figure 18 shows a graph of target metal precipitation versus pH at 75°C, 50 ml/min air using pH adjusted by automatic titration of 200 g/l Na ₂ CO ₃ . Solid-liquid separation was achieved at 180 min with addition of base at 150 min.
Figure 19 shows a graph of impurity element precipitation versus pH at 75° C., 50 ml/min air, using pH adjusted by automatic titration of 200 g/l Na ₂ CO ₃ . Solid-liquid separation was achieved at 180 min with base addition at 150 min.
Figure 20 shows the co-precipitation effect of final pH and initial NMC ratio on final NMC composition.
Figure 21 shows the extent of precipitation of Ca ²⁺ and Mg ²⁺ at various NMC final precipitation pH. Initial 50 mg/L Ca + 200 mg/L Mg in solution. NMC ratios were increased from 6:2:2 to 6:3:2 and 6:4 using an initial 0.12 mol/L Ni, 0.02 mol/L Co, and x mol/L Mn (x=0.02, 0.04, and 0.06) in solution. :Change it to 2.
Figure 22 shows precipitation percentages of Ni ²⁺ , Co ²⁺ and Mn ²⁺ at various NMC final precipitation pHs. The NMC ratio was increased from 6:2:2 (solid red dots) to 6:3: Change to 2 (red circle) and 6:4:2 (red rectangle).
Figure 23 depicts leaching recovery from a laterite ore sample according to one embodiment of the invention.
Figure 24 depicts recovery from NMC precipitation to solids of a laterite ore leach solution adjusted according to an embodiment of the invention.
Figure 25 depicts the leaching recovery from sulfuric acid leaching of MSP into solution according to an embodiment of the invention.
Figure 26 depicts recovery of solids from NMC precipitation of a sulfide concentrated leaching solution adjusted according to an embodiment of the invention.
Figure 27 depicts the leaching recovery from sulfuric acid leaching of blended cobalt concentrate/black mass into solution according to an embodiment of the present invention.

Exemplary methods of the present invention will now be discussed with reference to FIGS. 1-27.

A first exemplary method 10 of producing a co-precipitate comprising nickel, manganese and cobalt of the present invention is illustrated in FIG. 1 . The precipitation method mainly concerns after step (25).

The method includes treating a mixture 15 comprising nickel, cobalt and manganese with a reducing agent in an aqueous solution at a pH of about 1 to 6 (at 20). In the mixture 15, a portion of the nickel, cobalt and/or manganese is in an oxidized state, and upon treatment with a reducing agent, at least a portion of the oxidized nickel, cobalt and/or manganese is reduced and dissolved in an aqueous solution containing nickel, cobalt and manganese. This is provided.

The mixture is in particular a wet filtration cake obtained from the selective acid leaching (SAL) process disclosed in PCT/AU2012/000058 (although cathode materials containing nickel, cobalt and manganese from lithium-ion batteries can also be used). In general, a wet filter cake is obtained by contacting a mixed hydroxide precipitate comprising nickel, cobalt and manganese with an acidic solution containing an oxidizing agent at a pH that stabilizes the cobalt in the solid phase while dissolving the nickel in the acidic solution; The solid phase is then separated from the acidic solution, where the solid phase contains at least nickel, cobalt and manganese. In this exemplary embodiment, the solid phase is a wet filtration cake.

In the treatment steps using leaching and reducing agents, the wet filter cake is exposed to oxidized forms of cobalt, nickel and/or manganese, i.e. Co(III), Co(IV), Mn(III), Mn(IV), Mn(VII). ), Ni(III), or Ni(IV). However, this material may also contain significant amounts of unoxidized or reduced cobalt, manganese or nickel, for example in the form of Co(II), Mn(II) or Ni(II). Reduced cobalt, manganese and nickel are much more soluble in aqueous solutions at pH 1 to 6 than their oxidized forms.

As treatment steps are performed, the pH may decrease over time. The preferred pH for performing the treatment steps was a final pH of about 3-4 (under more aggressive conditions a final pH of about 2-3 may be suitable), with the pH being adjusted through the treatment steps through addition of additional leaching agent or base. was adjusted to this pH. The preferred leaching agent is sulfuric acid, but hydrochloric acid, nitric acid or organic acids may be suitable. The reducing agent in the treatment step is preferably sulfur dioxide gas, as it is sufficiently strong to reduce cobalt, manganese and nickel and does not introduce additional impurities into the aqueous solution. The addition of reducing agent was controlled in the treatment step to control the reduction of cobalt, nickel and/or manganese. Processing steps were performed in sealed containers to control gas loss. The reducing agent was added in a controlled manner using approximately 1 stoichiometric equivalent of reducing agent for the combined moles of oxidized cobalt, oxidized manganese and oxidized nickel in the mixture. The treatment step was carried out with stirring at a temperature of about 80°C to about 95°C for about 2 hours, or at a temperature of about 55°C with stirring for about 1-5 hours.

After the treatment step (20), the aqueous solution representing the aqueous feed solution of the present invention contains dissolved nickel, cobalt and manganese, and also arsenic, aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, ammonium, sulfite and fluorine. , fluoride, chloride, titanium, zinc, scandium and zirconium; In particular aluminum, copper and iron (e.g. if you start with black mass derived material) or zinc, calcium and magnesium (also iron and aluminum) (e.g. if you start with MHP derived material) Contains the same impurities. The aqueous solution also contained accompanying solids including impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc and zirconium.

After completion of treatment step 20, one or more impurities have been removed from the aqueous solution comprising dissolved nickel, cobalt and manganese. In the treatment step (20) the liquid together with the entrained solids was passed through a settling vessel for decanting/filtration (25) to remove the solids from the liquid. The solids removed from the settling vessel were returned to treatment step (20). The liquid removed from the settling vessel was further treated to remove impurities in (35). Exemplary impurities removed from the liquid may include iron, copper, zinc, and aluminum, which may be accomplished using precipitation and/or ion exchange separation techniques. For example, ion exchange can help remove at least some of the zinc.

After removal and/or separation of impurities, nickel, cobalt, and manganese co-precipitated from aqueous solution in (40). However, prior to co-precipitation, the ratios of nickel, cobalt and manganese can be adjusted to the desired ratio or additional cobalt, nickel and/or manganese can be added to provide the desired ratio in the co-precipitate. An exemplary ratio is 1:1:1 nickel:cobalt:manganese. The added cobalt, manganese and nickel may be in the form of CoSO ₄ , NiSO ₄ and/or MnSO ₄ or other cobalt, manganese and nickel containing compounds.

The co-precipitation step in (40) can be performed by adjusting the pH of the solution containing dissolved nickel, cobalt and manganese, preferably by adjusting the pH of the solution to about 7.5 to about 8.6. . This pH range has been found to result in less co-precipitation or incorporation of unwanted impurities, for example salts of magnesium and/or calcium, than when using higher pH ranges. This step was performed at 80°C and atmospheric pressure. Nickel, cobalt, and manganese were co-precipitated in the form of hydroxides. A two-step resuspension wash using 0.5% NH ₃ solution can be used.

The precipitate was then separated from the liquid by decanting or filtration, for example in (45). Advantageously, since some impurities such as sodium, potassium, magnesium, calcium, and sulfate remained in solution, further impurities are removed through the co-precipitation step. The liquid was further processed (e.g., precipitation or ion exchange) for nickel, manganese, or cobalt recovery in (55), and the solid was washed to remove additional impurities, then mixed with lithium and calcined in (50). The calcined product can be used to provide NMC material for use as the cathode active material (CAM) in new batteries.

A similar method 110 is shown in Figure 2. Similar numbers indicate similar characteristics. However, the method described in Figure 2 includes optional pre-washing. This can be washed using a mild acid leaching solution at a starting pH of about 3.5 (the pH increases as the wash progresses) to produce a solution containing about 10% solids. This pre-washing can remove at least some of the zinc, magnesium and calcium.

In contrast to that shown in Figure 1, the method shown in Figure 2 also uses a counter-flow setup, as described further below. In Figure 2, two mixing vessels (120a, 120b) and two settling vessels (125a, 125b) are used. As shown in FIG. 2, a mixture containing nickel, cobalt, and manganese is added to the aqueous solution in the first mixing vessel 120a and stirred. Solution (including entrained solids) leaves the first mixing vessel 120a through the first mixing vessel liquid outlet and enters the first settling vessel 125a through the first settling vessel liquid inlet. The first settling vessel 125a includes at least an upper outlet providing an outlet for liquid at the top of the vessel and a lower outlet providing an outlet for settled solids at the bottom of the vessel. The liquid leaving the first settling vessel through the upper outlet proceeds to a stage at 135 where liquid impurities in solution are separated. Liquid/solid leaving the first settling vessel 125a through the lower outlet flows into the second mixing vessel 120b through the second mixing vessel inlet. The reducing agent 105 and the leaching agent 108 were added to the stirred second mixing vessel 120b. Solution (including entrained solids) leaves the second mixing vessel 120b through the second mixing vessel liquid outlet and enters the second settling vessel 125b through the second settling vessel liquid inlet. The second settling vessel 125b includes at least an upper outlet providing an outlet for liquid at the top of the vessel and a lower outlet providing an outlet for settled solids at the bottom of the vessel. Liquid exiting the second settling vessel through the upper outlet flowed to the inlet of the first mixing vessel 120a. The liquid/solids leaving the second settling vessel through the lower outlet are disposed of at 130, for example after passing through a screw press. The advantage of this arrangement is that it minimizes the amount of acid and reducing agent remaining in the solution from which nickel, cobalt and manganese are co-precipitated. Additionally, the correct conditions were maintained to minimize the amount of iron in the first mixing vessel.

As in Figure 1, the mixture at 115 is a wet filtration cake obtained in particular from the selective acid leaching (SAL) process disclosed in PCT/AU2012/000058 (cathode materials containing nickel, cobalt and manganese from lithium-ion batteries can be used). Although you can). The SAL process was discussed in detail above, as were the oxidation states of cobalt, manganese, and nickel.

Once again, the preferred pH for performing the treatment steps was a pH of about 3, and throughout the treatment steps in mixing vessels 120a, 120b and settling vessels 125a, 125b the pH was adjusted to this level through the addition of additional leaching agent or base. Controlled by pH. The preferred leaching agent was sulfuric acid, but hydrochloric acid or nitric acid may also be suitable. The reducing agent in the treatment step is preferably sulfur dioxide gas, as it is sufficiently strong to reduce cobalt, manganese and nickel and does not introduce additional impurities into the aqueous solution. The addition of reducing agent was controlled during the processing steps to control the reduction of cobalt, nickel and/or manganese and optimize the utilization of the reducing agent. Processing steps were performed in sealed vessels to control gas losses (which required ventilation and off-gas scrubbing). The reducing agent was added in a controlled manner using approximately 1 stoichiometric equivalent of reducing agent for the combined moles of oxidized cobalt, oxidized manganese and oxidized nickel in the mixture. The treatment step was carried out with stirring at a temperature of about 55° C. for about 1-5 hours.

After treatment steps 120a and 120b, the aqueous solution contained dissolved nickel, cobalt and manganese, as well as impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc and zirconium. The aqueous solution also contained accompanying solids including impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc and zirconium.

The liquid removed from the first settling vessel 125a was further processed at 135 to remove impurities. Exemplary impurities removed from the liquid may include iron, copper, zinc, and aluminum, which may be accomplished using precipitation and/or ion exchange separation techniques.

After removal and/or separation of impurities, nickel, cobalt and manganese co-precipitated from aqueous solution at (140). However, prior to co-precipitation, additional cobalt, nickel and/or manganese can be added to adjust the ratios of nickel, cobalt and manganese to the desired ratio as described above with respect to Figure 1. The co-precipitation step in (140) is the same as described above for Figure 1.

The precipitate is then separated from the liquid, for example by decanting or filtration. The liquid was further processed (e.g., precipitation or ion exchange) for nickel, manganese, or cobalt recovery in (155), and the solid was washed to remove additional impurities in (150) and then mixed with lithium and calcined. The calcined product can be used to provide NMC material for use as the cathode active material (CAM) in new batteries.

In a further embodiment, the method outlined in Figures 10 or 11 may be used in the method outlined in Figures 1 and 2 prior to the impurity separation/co-precipitation step. In these methods, the oxidized nickel, cobalt, manganese material 201 (Figure 10) or the reduced nickel, cobalt, manganese material 251 (Figure 11) is dissolved in acid (203/253), optionally water (205/255). , and an oxidizing agent 207 or a reducing agent 257 (depending on the starting material) to bring the pH to about 1 to about 6 or about 1 and about 7. After leaching the resulting solution in the leaching vessel 210/260, the leachate may be filtered 215/265 and impurity solids 218/268 removed. Accordingly, the leachate passes through the treatment vessel 220/270 (Note: the leach vessel 210/260 may be the same as the treatment vessel 220/270) and the oxidizer 222 (oxidized NMC material 201 ) or reducing agent 272 (if starting with reduced NMC material 251) is added to neutralize excess reducing agent 207 or oxidizing agent 257 remaining in the leachate. Base 224/274 may also be added to increase the pH (e.g., the solution in the leaching vessel may have a pH of about 3 and the solution in the processing vessel may have a pH of about 6). As a result, some material may settle in the processing vessel 220/270, which may then be filtered (230/280) to provide impure solids (232/282) and NMC solution (234/284).

Exemplary results of the method are provided below.

leaching

Example 1 : Starting material derived from MHP

Acid pre-wash

In this experiment, cobalt concentrate from a pilot plant (Brisbane Metallurgy Laboratories) was used. The cobalt concentrate had the following elemental composition based on total dissolution and percent solution assay: 61.5 Ni, 18.3 Mn, 15.0 Co, 1.6 Na, 0.9 Zn, 0.9 Mg, 0.7 Fe, 0.4 Cu, 0.4 Al, 0.2 Ca. This cobalt concentrate was prepared in the SAL process using mixed hydroxide precipitate (MHP - solid mixed nickel-cobalt hydroxide precipitate). contacting the MHP with an acidic solution containing an oxidizing agent at a pH where the cobalt is stabilized in the solid phase and the nickel is soluble in the acidic solution; The solid phase containing nickel, cobalt and manganese was then separated from the acidic solution.

The cobalt concentrate was washed with mild acid to reduce the impurity content associated with the entrained solution and residual nickel hydroxide. Due to the high solution retention of solids upon filtration, a combination of re-slurry wash and displacement wash using a pressure filter was used in this example.

In this process, cobalt concentrate (180 g dry solids) was first mixed with 5 g/LH ₂ SO ₄ at room temperature to produce a slurry with 20 wt % solids. The slurry was then washed by pressure filtration; (i) stop filtration after about 200 mL of solution has been recovered; (ii) The filter was depressurized, 200 mL of 1g/LH ₂ SO ₄ was added to the filter, and filtration was resumed. Steps (i) and (ii) were repeated until a total of 1 L of 1 g/LH ₂ SO ₄ was added to the filter. The remaining solution was filtered and collected in batches of approximately 200 mL. After the last solution was withdrawn, air was blown through the filter for 30 minutes.

As shown in Tables 1, 2 and Figure 3, this process was effective in reducing the Ca (93%) and Mg (93%) contents of the leached solids, with moderate effectiveness for Ni and Zn (60%). There was. Co and Mn losses to solution were negligible (<10 mg loss in 180 g dry solids feed). Fe was absent and Cu was minimally washed away. The last 500 mL of 1 L acid wash solution contains virtually no dissolved metals.

Table 1 : Results of the acid pre-wash step - cobalt concentrated starting material and acid pre-washed cobalt filtration cake

Table 2 : Percentage of minerals washed in acid pre-cleaned cobalt filtration cake (compared to minerals in cobalt concentrate)

Reducing agent and acid treatment

The washed cobalt concentrate was slurried to 5 wt%, heated, and SO ₂ was bubbled into the reactor to reduce the solid to pH 4, which was set as the end point of the experiment. This endpoint was chosen because it had some selectivity for impurity elements and showed good recovery in previous tests. Due to a calculation error, the initial SO ₂ flow rate was too low and had to be increased to complete the experiment.

In this process, the washed cobalt concentrate was first slurried with 5% solids in deionized water and heated to 55°C. Next, 12 mL/min SO ₂ was bubbled into the slurry for 5 hours. The SO ₂ flow rate was then increased to 36 mL/min for an additional 110 minutes until the solution pH reached 4. Finally, the slurry was filtered and the solution (filtrate) was recovered.

As shown in Table 3 and Figures 4a and 4b, treatment with reducing agents and acids recovered >90% of the target metals (Ni, Mn and Co). Slow addition of SO ₂ enabled selective leaching of target metals for Al, Cu, and Fe until near the end point. Ca and Mg leached faster than the target elements, but final solution concentrations were low (<30 mg/L) due to effective pickling of the feed solids.

Table 3 : Analysis of treatments using reducing agents under acidic conditions

Without wishing to be bound by theory, the inventors believe that initially the acid forming reaction of SO ₂ and water is overwhelmed by the reduction of Co ³⁺ and Mn ⁴⁺ hydroxides, causing an increase in pH. Once most of the reduction is largely complete, the pH drops until it is buffered by dissolution of the divalent hydroxide around pH 5, and falls further as recovery into solution approaches maximum.

Giving back ends

The filtrate from the previous paragraph was contacted with acid washed cobalt concentrate (as an oxidizing agent) at 80° C. to consume any SO ₂ remaining dissolved in solution and precipitate the iron. MnCO ₃ was added to increase the pH and aid impurity precipitation while offsetting the expected Mn loss from ion exchange (IX), but the pH remained stable (approximately pH 4.8) due to the buffering effect of the impurity precipitation reaction.

In this process, the filtrate was first slurried with washed cobalt concentrate to 5% solids (50 g) and heated to 80°C. After 1 hour, 13.8 g of MnCO ₃ was added to the slurry, and after 8 hours, the slurry was filtered. The pH range at this stage of the process was 5.1-4.6.

As illustrated in Table 4 and Figures 5a, 5b, and 5c, contact of added MnCO ₃ with a leaching solution with unleached solids at 80°C results in rapid removal of Al, Cu, and Fe (within a few minutes of contact with the solids). within minutes). The Ni and Co concentrations remained relatively stable, with Mn initially precipitating and then gradually increasing after the addition of MnCO ₃ .

Table 4 : Concentrations of various metals at the beginning and end of the reduction step.

In previous oxidation tests without the addition of MnCO ₃ , the concentrations of Co, Ni and Zn in solution all increased with much lower final Mn concentrations (similar to the precipitation seen in this experiment without subsequent dissolution). Despite the MnCO ₃ addition, the pH remained relatively stable (5.04 immediately after solid addition and 4.67-4.87 for the remainder of the test).

Ion exchange (IX)

The filtrate from the previous paragraph was contacted with Lewatit® VP OC 1026 macroporous ion exchange resin (based on styrene divinylbenzole copolymer containing di-2-ethylhexyl phosphate (D2EHPA); the resin is available from Lanxess, Cologne). . Contacting with the ion exchange resin was carried out in two steps at 40°C. pH control was performed using 0.1MH ₂ SO ₄ and 1M NaOH before IX contact and the target pH was 3.8-3.9. The resin was acid washed with 10% H ₂ SO ₄ and then adjusted to pH 3.5 before use. Additions in the following paragraphs below are given in volume of resin as received, taking into account mass changes during washing.

1. Put 250 mL of filtrate into a bottle and adjust the pH to 3.9.

2. Add 120 mL of resin, seal the bottle and place it on a bottle roller at 40°C for 24 hours.

3. The resin was filtered and the solution was added to a clean bottle.

4. The pH was adjusted to 3.8.

5. 120 mL of resin was added, the bottle was sealed, and placed on a bottle roller at 40°C for 4 hours.

6. The resin was filtered and the solution was recovered.

Based on previous ion exchange (IX) tests, two contacts connected in series at 40 °C with minimal pH control were chosen to maximize Zn removal and minimize Mn loss. Tables 5 and 6 show the solution assay results before and after each contact. The dilution correction assay takes into account the solution remaining in the resin due to cleaning and conditioning. Both contacts showed excellent Zn removal rates (87% and 91%) compared to previous experiments, while Mn loss was not fully alleviated (15% and 16%). Some Al and Ca were also removed (cumulative 29% and 32%, respectively), and Fe entering IX was <1 mg/L.

Table 5 : Concentrations of various metals during ion exchange treatment.

Table 6 : Ion exchange results, percentage of various metals on resin

Example 2 : Lithium-ion battery derived starting material (black mass)

materials and equipment

The reagents used in this work were food grade SO ₂ and reagent grade 98% H ₂ SO ₄ . The composition of the black mass samples used is provided in Table 7. This sample was obtained from a lithium-ion battery that had been shredded and chemically cleaned.

Table 7 : Elemental concentrations of major elements in black mass samples

All reactions were completed in a 1.1 L baffled glass reactor. The temperature was maintained by a hot plate with thermocouple feedback control. Agitation was achieved by an overhead stirrer set at 800 RPM using a high shear Teflon impeller. Gas was sparged using a glass sparging rod connected to a gas flow meter to control the rate of gas addition. Care was taken to ensure that the sparger was submerged at a consistent level consistent with the blades of the impeller to ensure maximum gas dispersion during the reaction.

methodology

First, the required amount of black mass was weighed and placed directly into the reactor. The required amount of water was then added and the reactor was heated to the reaction temperature. Once the reaction temperature was reached, initial samples were taken by pipetting and cooled to room temperature in sealed syringes. Once cooled, the sample was syringe filtered and diluted with nitric acid, returning excess sample to the reactor. If applicable, the hoses of the SO ₂ sparge and acid pump were inserted into the reactor and timing was started. As an overview of the initial samples, samples were taken at time intervals predetermined by the experiment according to the sampling methodology.

Once the reaction time had elapsed, the reactor was weighed for mass balance and the slurry was vacuum filtered. The wet solid was then dried at 105° C. overnight and the solution was stored in a glass bottle.

SO ₂ and H ₂ SO ₄ addition rates were calculated based on the flow rate required to administer 100% of the stoichiometric dose to react all Li, Ni, Mn, and Co to the divalent state in the required time. This assumes that both Ni and Co exist in trivalent form and that Mn exists in tetravalent form.

Results - Impact of Sample Type

Four different black mass samples were treated using only SO ₂ gas as reducing agent without adding additional acid at 55°C. These conditions were chosen as an initial baseline because they provide a point of comparison to previously completed reductive leaching tests performed on cobalt concentrate materials. All tests were performed at 5% solids concentration. 5% solids was chosen to preserve sample mass and target a total metal concentration of approximately 0.2 M in the final solution. A metal concentration of 0.2 M was chosen as the target for subsequent NMC precipitation operations. Full experimental details of the tests performed are provided in Table 8.

Table 8 : Summary of experimental conditions

The extent of leaching and pH profiles as a function of time for the tests summarized in Table 7 are presented in Figures 6A-6D. Comparing these results, it is clear that BMJ-B outperformed the other samples tested. BMJ-B is very amorphous in nature, showing much higher reactivity compared to more crystalline samples. The inventors believe that this is likely caused by removal of lithium from the sample. This material was delithiated, destroying the crystal structure and making the sample amorphous. As a result, the kinetics became faster and a cobalt recovery rate of more than 90% was achieved within 5 hours. The Canadian sample (BMC) had the highest impurities and the least pretreatment of all samples. BMC performed similarly in terms of cobalt recovery, but achieved only 75% nickel recovery. The inventors believe that the improved performance of this sample is expected to be due to the higher concentration of metallic impurities (Al, Cu and Fe metals), which can act as reducing agents and improve recovery. Both BMJ-A and the Korean sample (BMK) were pure and highly crystalline samples, and both had only a 50% recovery rate of Ni, Co, and Mn within 5 hours. Given this, BMK was chosen as a representative sample for all further tests as it had sufficient sample mass and was equivalent to the most difficult to leach sample. The most difficult was chosen as this material can be leached, so that all black mass samples can be leached under similar conditions.

Results - Impact of reagent dosing rate

Five experiments were performed to investigate the effect of reagent addition rate. All samples used BMK solids at 55°C and 5% solids concentration. SO ₂ and acid (20% H ₂ SO ₄ ) were then added to the reactor according to Table 9. For continuous acid testing, acid was added via a peristaltic pump.

Table 9 : Summary of experimental conditions

Solution recoveries for the tests summarized in Table 9 are shown in Figures 7A-7D. Comparing Figures 7a-7d with Figure 6d, addition of H ₂ SO ₄ at any dose significantly improved recovery and kinetics.

Stepwise addition of acid (Figure 7a) with 100% stoichiometric SO ₂ in 2.5 h improved the recovery from 50% in 5 h to over 80% in 5 h. The experiment involved 6 hours, before which a large amount of acid was added to lower the pH to below 3. As a result, Co and Ni recovery rates increased immediately (5%). During this final time, the recovery of all target metals increased up to 90%, indicating that the system was still limited by the acid.

In the slow continuous acid test (Figure 7b), acid was supplied via a peristaltic pump to deliver 100% stoichiometric acid demand in 2.5 h using 100% stoichiometric SO ₂ in 200 min. This test showed that more than 90% of the target metal was recovered in 180 minutes. The recovery did not change significantly after this point, indicating that the reaction was complete. This recovery value is based on a solution assay and solids analysis actually showed a recovery of over 98% for this test. Therefore, the leaching range in the graph is biased low as the calculated heads from the final solution and final solid assays should be more accurate.

In a fast series test (Figure 7c), both acid flow rate and SO ₂ addition were increased to supply 100% of the stoichiometric requirement within 90 min. It was shown that under these conditions, approximately 100% of all target metals were extracted in 90 minutes. After this point there was little change in the target metal recovery, but impurity elements continued to be recovered. At 90 minutes, 40% of aluminum and 10% of iron were recovered from the solution, increasing to 60% and 15%, respectively, after 2.5 hours. This shows that there is no advantage in extending the reaction time further than that required to provide 100% reagent coverage. Comparing the impurity recovery from this test (Figure 7c) with the slow acid test (Figure 7b) showed some improvement in selectivity at slow addition rates. Maximum recovery was achieved in 150 minutes at a slow speed. At this point, only 10% Al and 2% Fe were recovered. Comparing this with the rapid addition of 90 minutes, the impurity recovery rate was found to increase by about 6 times.

Figure 7d shows the results of the immediate acid test. In this experiment, 100% of the stoichiometric acid requirement was added at the start of the experiment and stoichiometric addition of SO ₂ was achieved in 30 minutes. Addition of all acids was found to be sufficient to recover 35-40% of Ni, Mn, and Co and 90% of Li. These recoveries increased to over 90% for all metals within 30 minutes. After 30 minutes, the recovery of all target metals slowly decreases to 85-90% over a reaction time of 2.5 hours. Nickel fell sharply at the 60-minute mark. This point is believed to be an outlier caused by a dilution error. Aluminum recovered quickly to 60% after adding acid, and this value increased gently over time, up to 78%. The iron recovery rate was constant at 10-11% even after acid recovery. This shows approximately similar selectivity to the fast continuous acid test, but with significantly increased kinetics.

The final test (reference example) was completed using acid and no SO ₂ (Figure 7E). After 5 hours, only 30-40% of Ni, Mn, and Co were recovered, and 80% of Li was recovered. These results correspond to the recoveries obtained in the immediate acid test before adding SO ₂ . This shows that for the BMK sample, approximately 40% of Ni, Mn, and Co are dissolved without a reducing agent.

Results - Effect of Solids Concentration

An experiment was performed to investigate the effect of higher solid concentration on the extent and kinetics of the reaction. Higher solids concentrations were chosen for investigation as they produce more concentrated leaching solutions. This increases the efficiency of downstream impurity separation and reduces the reactor volume required depending on the set throughput. In this test, BMK solids were reacted at 55°C to a 20% solids concentration. Acid was added continuously under conditions similar to the fast continuous acid test (2.9 ml/min 50% H ₂ SO ₄ , 290 ml/min SO ₂ ). In this experiment, 50% H ₂ SO ₄ was used to prevent overflow in the reactor. This high acid strength caused excessive heating of the solution, raising the temperature to approximately 75°C during the first 30 minutes. The reactor was then transferred to a cooled water bath and the temperature was kept constant at approximately 45°C. Because of this, the effects of solid concentration and temperature cannot be completely separated and this must be kept in mind when interpreting the results.

Figure 8 shows the results of an experiment performed at 20% solids using fast continuous reagent conditions. Compared to the equivalent test at 5% solids, overall recovery and reaction kinetics were reduced, with only 80% recovery achieved after 2 hours. However, at the end of the experiment, the recovery rate tended to increase, so it is expected that complete dissolution is possible at 20% solids.

Results - Effect of reaction temperature

Two experiments were performed to investigate the effect of temperature on the extent and kinetics of the reaction. Higher temperatures were investigated to further improve the reaction kinetics by increasing the dissolution rate. BMK solid was reacted at 75°C to 5% solid concentration. Acid was added continuously under conditions similar to the fast continuous acid test (2.2 ml/min 20% H ₂ SO ₄ , 52 ml/min SO ₂ ). Values exceeding 100% are shown in Figure 9a but are most likely due to evaporation. Due to errors in experimental mass recording, mass loss due to evaporation could not be estimated.

Lower temperatures were investigated in an attempt to further improve the reaction kinetics by increasing the solubility of SO ₂ gas into the solution. BMK solid was reacted at 5% solid concentration at room temperature. During the experiment, the temperature naturally rose between 30℃ and 35℃. Acid was added continuously under conditions similar to the fast continuous acid test (2.2 ml/min 20% H ₂ SO ₄ , 52 ml/min SO ₂ ). Values exceeding 100% are shown in Figure 9b but are most likely due to evaporation. Due to errors in experimental mass recording, mass loss due to evaporation could not be estimated.

As can be seen in Figure 9a, as the reaction temperature increased, performance deteriorated compared to the equivalent test at 55°C. At 75°C, recovery, selectivity, and kinetics were all negatively affected by increasing reaction temperature. The inventors believe that this is likely due to reduced SO ₂ solubility, resulting in slower reduction of the metal. Likewise, lowering the reaction temperature also had a negative effect on recovery and kinetics. A reaction time of 120-150 minutes was required to achieve recoveries greater than 90% for all target metals at 35°C.

precipitation

Removal of impurities by ion exchange (IX)

The feed solution with the composition given below was contacted with Lewatit® VP OC 1026 macroporous ion exchange resin (based on styrene divinylbenzole copolymer containing di-2-ethylhexyl phosphate (D2EHPA); the resin is available from Lanxess). .

Contacting with the ion exchange resin was carried out in two steps at 40°C. pH control was performed using 0.1MH ₂ SO ₄ and 1M NaOH before IX contact and the target pH was 3.8-3.9. The resin was acid washed with 10% H ₂ SO ₄ and then adjusted to pH 3.5 before use. Additives in the following paragraphs below are given in volume of resin as received, taking into account mass changes during washing.

7. 250 mL of filtrate was added to the bottle and the pH was adjusted to 3.9.

8. Add 120 mL of resin, seal the bottle and place it on a bottle roller at 40°C for 24 hours.

9. The resin was filtered and the solution was added to a clean bottle.

10. The pH was adjusted to 3.8.

11. Add 120 mL of resin, seal the bottle and place it on a bottle roller at 40°C for 4 hours.

12. The resin was filtered and the solution was recovered.

Based on previous ion exchange (IX) tests, two contacts connected in series at 40 °C with minimal pH control were chosen to maximize Zn removal and minimize Mn loss. Tables 10 and 11 show the solution assay results before and after each contact. The dilution correction assay takes into account the solution remaining in the resin due to cleaning and conditioning. Both contacts showed excellent Zn removal rates (87% and 91%) compared to previous experiments, while Mn loss was not fully alleviated (15% and 16%). Some Al and Ca were also removed (cumulative 29% and 32%, respectively), and Fe entering IX was <1 mg/L.

Table 10 : Concentrations of various metals during ion exchange treatment.

Table 11 : Ion exchange results, percentage of various metals on resin

Removal of impurities from feed solution

This experiment summarizes investigations into the removal of impurities from synthetic solutions. Synthetic solutions were used to ensure repeatability and sufficient sample size. This solution was created to mimic the concentration and pH of the solution produced during leaching. The main parameters investigated in this report were pH and base type.

It was demonstrated that by increasing the pH to 6.2, 100% of aluminum, copper, chromium, iron and zinc impurities could be removed from the solution. It has been shown that at pH 5-5.5 all aluminum, chromium and iron are removed as well as most copper. There was no significant precipitation of zinc until pH 6, when 95% of the zinc and the remaining copper were lost. Increasing the pH to 6.2 removes the remaining zinc, producing a solution free of impurities (except Ca and Mg). A pH of 6.2 was required to reach the calculated solution specifications. Increasing the pH to 6.2 results in a loss of approximately 25% Ni, 15% Co, and 10% Mn.

Three different base types were tested. Sodium hydroxide and sodium carbonate gave almost identical results. All impurities precipitated at the same pH and loss of target metal was consistent for both bases. However, when sodium carbonate was used, the filtration properties of the resulting solid were much better. A combination of manganese carbonate and basic nickel carbonate gives similar results to sodium carbonate. However, it was found that manganese carbonate was not completely dissolved, resulting in waste manganese. For this reason, it is recommended to use sodium carbonate as a base to remove impurities.

There was a clear opportunity to perform impurity removal in two stages. First, at pH 5.5, most solution impurities can be removed. This solid material can be separated from the solution and disposed of as waste. The excellent filtration properties of carbonate solids allow for quick and easy separation of solids. After this step, the partially purified solution should contain only trace amounts of copper and zinc as impurities. By increasing the pH above 6 (ideally 6.2), the remaining copper and zinc can be removed from the solution. This also results in losses of nickel, cobalt and manganese, making this solid stream of high value. This material can be collected and returned to SAL leaching to recover copper and remove zinc impurities from the system. This concept was demonstrated at laboratory scale, including solid/liquid separation between two desired pH levels (5.5 and 6.2). It was shown that by including solid-liquid separation, losses of cobalt, nickel, and manganese could be limited to 5%, 10%, and 0%, respectively.

The results presented here highlight the possibility of eliminating ion exchange from the process. The results of this experiment show that a high-purity solution can be produced through precipitation alone, eliminating the need for an expensive ion exchange process.

introduction

Based on the known pH dependence for the solubility of metal hydroxides, it was considered possible to selectively remove hydroxides from solution. The impurities considered were iron, aluminum, copper and calcium. However, testing of black mass samples showed that they may contain magnesium and zinc. The parameters tested in this study were pH and base type.

Materials and Methods

matter

The reagents used in this work were all reagent grade except food grade SO ₂ . Chemicals used and target concentrations in stock solutions are shown in Table 12.

Table 12 : Stock solution concentrations

The solution concentration was chosen to be representative of the solution produced through leaching of black mass. Impurity elements were added to simulate higher-than-expected impurity concentrations. The pH was initially lowered to the target value of 1. This was exceeded by approximately pH 0.5. However, this starting pH was too low and caused volume issues during sedimentation tests. To solve this, NaOH was used to increase the pH to 2.6. SO ₂ was then sparged into the reactor until the solution was saturated to better mimic the solution produced during leaching. After this, the pH was once again increased to 2.6.

equipment

All reactions were completed in a 1.1 L baffled glass reactor. The temperature was maintained by a hot plate with thermocouple feedback control. Agitation was achieved by an overhead stirrer set at 800 RPM using a high shear Teflon impeller. Gas was sparged using a glass sparging rod connected to a gas flow meter to control the rate of gas addition. Care was taken to ensure that the sparger was submerged at a consistent level consistent with the blades of the impeller to ensure maximum gas dispersion during the reaction. The pH was controlled using a Metrohm automatic titrator connected to a high temperature pH probe and a PID program running through a connected laptop.

methodology

First, the required amount of stock synthesis solution was weighed and placed directly into the reactor, and the reactor was heated to the reaction temperature. Once the reaction temperature was reached, the initial sample was taken and cooled to room temperature in a sealed syringe. Once cooled, the sample was syringe filtered and diluted with nitric acid, returning excess sample to the reactor. The titrator's air sparge and hose were then inserted into the reactor and reagent dosing and timing began. Samples were collected at time intervals predetermined by the experiment, following the same sampling method.

Once the experiment was complete, the reactor was weighed and the slurry was centrifuged for hydroxide samples or vacuum filtered for carbonate samples. The wet solid was then dried at 105° C. overnight and the solution was stored in a glass bottle. Density readings were taken before and after the reaction.

To determine whether the experiment successfully achieved the required solution purity, a set of solution target concentrations was calculated. These targets are presented in Table 13 and were calculated assuming 100% delivery to the final precipitated NMC product.

Table 13 : Solution concentration targets. *Based on assumptions

result

Effect of pH

Test conditions and validity

pH is an important parameter for determining the separation efficiency of impurity elements from the target metal. To investigate the effect of pH, base (2.5 M NaOH) was added to the stock solution using an automatic titrator to maintain the solution at the target pH. Samples were taken after this target pH was reached and maintained at this pH for 1 hour. After the second sample, the pH regulator was adjusted to the next level and the process was repeated. The temperature was kept constant at 75°C throughout each experiment. In this manner three experiments were carried out, the results of the most conclusive tests being presented in this report, the others being referred to for particulars.

Results and Discussion

Based on visual observation and base dosage and pH trends, the first precipitation began to occur at pH 3.6-4. After the solution was kept at pH 4 for 1 hour, more than 90% of Fe and almost all of Al and Cr were removed from the solution. Further increasing the pH to 5 resulted in complete removal of Fe, Al, and Cr and 65% removal of Cu impurity. To completely remove Cu, the solution had to be increased to pH 6, at which point 94% of the Zn was also removed. To meet the zinc solution specification outline in Table 11, the pH had to be raised to 6.2. However, at pH 6.2, there was a loss of 11% of cobalt, 21% of nickel, and 7% of manganese. If the pH is raised beyond this point, more than 90% of nickel, 80% of cobalt, and 40% of manganese are lost. The major pH buffering appears to occur at approximately pH 6.4. It therefore represents an upper limit that should not be exceeded to reduce the loss of the target metal.

Additionally, rapid base administration up to pH 5 was found to increase nickel loss at lower pH. With rapid base addition, 15% of nickel was precipitated together with impurity elements. Therefore, it is recommended to slowly increase the pH to pH 5.5 over 2 hours. It should be held for 1 hour to maximize copper precipitation. The solution should then be raised to pH 6.2 and immediately removed from solution. This is based on the observation that the zinc and copper specifications are met at this point and further maintenance of pH 6.2 only increases the losses of nickel, cobalt and manganese.

Effect of base type

Test conditions and validity

Two additional tests were performed to investigate alternative bases using methods similar to those described in the previous section. Sodium carbonate is an ideal candidate to replace NaOH, the base used to remove impurities, because it is equally available but generally cheaper to supply. Additionally, carbonate anions may provide additional impurity removal advantages over hydroxides.

The second alternative base investigated is a combination of sodium carbonate with solid manganese carbonate and basic nickel carbonate (BNC). These chemicals are cheaper and can be used in the field, providing an opportunity to reduce reagent costs. For this test, a certain amount of manganese carbonate and BNC were added as solids so that the final solution had a 6:4:2 Ni:Mn:Co ratio after removal of impurities to reflect the ongoing development of NMC precipitation equipment. This represents the theoretical maximum amount of these compounds that must be added, requiring the administration of further expensive cobalt salts. Metal salt was added at time 0 and reacted for 1 hour. After this point, sodium carbonate was added to further adjust the pH according to other experiments.

Results and Discussion

Comparing the results shown in Figures 14 and 15 with the NaOH results, it can be seen that there is no significant difference between the two base types. Table 14 compares the key considerations for the two bases. This indicates that impurity elements were removed in the same step when using Na ₂ CO ₃ compared to NaOH. The amount of target metal lost after precipitation was constant. Therefore, it can be concluded that precipitation occurs as a result of increasing pH and that carbonate anions do not improve precipitation. However, it is important to remember that Na ₂ CO ₃ has powerful advantages in material handling. Solids formed during carbonate precipitation settle and filter out much more easily than solids formed during hydroxide precipitation.

Table 14: Comparison of NaOH and Na ₂ CO ₃ base types. The pH value lists the point at which all specifications in Table 11 are met.

The addition of MnCO ₃ and BNC resulted in no advantage over Na ₂ CO ₃ alone tested (see Figures 16 and 17). Removal of impurities was achieved at the same pH and level. However, MnCO ₃ was not completely dissolved, indicating that its ability to act as a base in this situation was limited. More than 100% of nickel was recovered due to BNC dissolution, indicating that the assumption that BNC exists as a tetrahydrate is incorrect. All BNC can be assumed to be dissolved and could theoretically be used as a base if the molar ratio allows adding additional nickel to the system prior to NMC precipitation.

Stage 2 sedimentation effect

Based on the results of the Na ₂ CO ₃ and NaOH precipitation experiments, there appears to be an opportunity to split the device into two tasks at two pH levels. By first precipitation at pH 5.5, all Al, Cr and Fe can be removed along with about 90% and 10% Cu and Zn, respectively. This can be achieved while minimizing loss of target metal. Solid/liquid separation can then be used to remove unwanted, low-value waste materials. The solution can then be increased to pH 6.2 to remove any remaining Cu and Zn. This was accompanied by a loss of about 30% Ni, 20% Co loss, and 10% Mn loss. This material is of high value and can be collected and recycled up to the early stages of the process.

To test this concept, an experiment was performed where the pH was slowly increased to 5.5 over approximately 1.5 hours using a 200 g/l Na ₂ CO ₃ solution. It was then held at this pH for 1 hour before vacuum filtration. The clear solution was then reheated and base dosage resumed to achieve pH 6.2. This was held for 1 hour before final solid/liquid separation.

Results and Discussion

In contrast to the expected results, much less material was observed to precipitate at pH 6.2 when solid/liquid separation was complete between the two steps. This observation is supported by the results presented in Figures 18 and 19. From these results, it is clear that including solid/liquid separation significantly improves the retention of Ni, Co, and Mn without affecting impurity removal. The results of this test relative to the single step Na ₂ CO ₃ N test are presented in Table 15.

Table 15: Comparison of NaOH and Na ₂ CO ₃ base types. The pH value lists the point at which all specifications in Table 11 are met.

Formation of co-precipitate

The purpose of this experiment is to investigate impurity precipitation as a function of NMC precipitation - pH test. The objective is to identify a suitable pH range and solution conditions at which the NMC precursor can be precipitated to achieve appropriate major element chemistry (Ni/Co/Mn) while being selective for impurities Ca and Mg. In the slightly alkaline pH range (pH 7.6-8.0), most impurity ions (Ca ²⁺ and Mg ²⁺ ) did not appear to co-precipitate with the NMC precursor. The results suggest that this approach is possible to produce NMC precursors by adjusting the initial NMC composition, alkalinity type and amount in solution.

experimental

500 mL of NMC initial solution (total NMC of 0.2-0.24 M, see Figure 20 for specific samples) was pumped into a 1 L reactor containing 200 mL of ammonium solution (0.1 M) at a rate of 8 mL/min by peristaltic pumping. supplied to. After 3 minutes, 480 mL of alkaline solution (0.20-0.24M) is pumped into the same reactor at the same flow rate. After 60 minutes, all remaining liquid was pumped into the reactor. A hot plate was used to heat the reactor to 80°C under an inert gas (N ₂ ) atmosphere. The transition metal and alkaline solutions were mixed vigorously in a 1 L reactor while pumping (1 h) using an overhead mechanical stirrer at 800 rpm. The stirring speed is then maintained at 800 rpm for the next 4 hours until 5 PM. For safety reasons the stirring speed during the subsequent hours was set at 600 rpm for 15-16 hours. Total settling time is in the range of 20-21 hours. Afterwards, the reactor was cooled from 80°C to room temperature. The final slurry was vacuum filtered to obtain a precipitate. The final solution pH of different samples is listed in Figure 20. The obtained precipitate was washed in two steps. Primary washing involves repulping the sediment with 0.1 M NaOH solution (~5% solids content) using magnetic stirring at 80°C for 60 min followed by solid/liquid separation using a vacuum filter. In the second washing, the sediment from the first washing was repulped with a 2% NH ₃ H ₂ O solution (~5% solid content) using magnetic stirring at 80°C for 60 minutes, and then separated into solids/solids using a vacuum filter. The final NMC precursor solid is obtained by separating the liquid. The NMC precursor was then dried in an oven at 105°C for 8-10 hours to separate the free moisture. After drying, the precipitate is sent for lithiation and then for the manufacture of coin cell batteries. The final NMC ratios of the precursors are listed in Figure 20.

Except for sample 8, which was prepared by actual leaching solution, all NMC 44-52 samples were prepared by synthetic initial NMC solution dissolving analytical grade nickel, cobalt and manganese sulfates in DI water. Some of these synthetic initial NMC solutions contained 20 mg/L Ca and 200 mg/L Mg.

The chemical composition of the NMC initial solution contained 0.2-0.24 M total Ni + Co + Mn (NMC). The NMC molar ratio of the NMC initial solution is designated by the Y-axis labels in Figure 20. For example, in Figure 20, " NMC 44 (initial 6.1:1.8:2.1) pH 9.20 " indicates that this NMC initial solution (NMC 44 sample) had an initial NMC ratio of 6.1:1.8:2.1. Additionally, once precipitation was complete, the final solution pH was equal to 9.20 for “ NMC 44 (initial 6.1:1.8:2.1) pH 9.20 ” in Figure 20.

Results and Discussion

Figure 21 shows that the degree of precipitation of Ca ²⁺ and Mg ²⁺ (from initial feed solution concentrations of 50 and 200 mg/L, respectively) is up to 88.6% of Ca in the alkaline pH region (8.1-9.3) and 71.4% of Mg at pH 9.3. while the precipitation rates of Ca ²⁺ (5-18%) and Mg ²⁺ (1-3%) remain low at pH < 8.

Figure 22 shows that the precipitation percentages of Ni ²⁺ , Co ²⁺ and Mn ²⁺ are significantly higher (98-100%) when the final pH is >8.6. In the slightly alkaline pH region (8-8.2), the precipitation rates of Ni ²⁺ and Co ²⁺ are still quite similar in the 90-100% range, while the precipitation rates of Mn ²⁺ are relatively lower than those of Ni ²⁺ and Co ²⁺ . Precipitating the correct chemical composition of NMC622 becomes complicated. Specifically, the initial Mn ²⁺ concentration increases from C _Mn =0.02M (initially 6:2:2) to C _Mn =0.04M (initially 6:3:2) and 0.06M (initially 6:4:2). The precipitation rate of Mn ²⁺ decreased from ~80% to ~70%. In the slightly alkaline pH region (7.6-8.0), the precipitation rates of Ni ²⁺ and Co ²⁺ are still similar in the range of 80-90%, while the precipitation rate of Mn ²⁺ is about 70% at initial C _Mn = 0.06 M (initial 6 : 4:2). The initial concentration of Mn was varied throughout the test to achieve an accurate final Mn concentration in the sediment.

There are some outlier data points for the Mn precipitation percentage shown in Figure 22. For example, at pH=7.9 (NMC 52 sample) the precipitation percentage of Mn ²⁺ reached 94%, similar to the values of Ni ²⁺ and Co ²⁺ . These outliers are due to Mn oxidation from +2 to +4 by air during the NMC precipitation process without N ₂ gas protection (depletion of the N ₂ gas cylinder). Another repeat test using N ₂ gas protection during NMC precipitation (NMC 52-R sample, see Table 10) resulted in a Mn ²⁺ precipitation percentage of ~70% at pH=7.87. The results confirmed this hypothesis. Since the literature suggests that N ₂ protection during NMC precipitation is necessary, additional battery performance testing for NMC 52 and NMC 52-R may reveal whether N ₂ protection during NMC precipitation is essential for battery performance. Another outlier data at pH=7.7 is due to a leak in the precipitation reactor.

The results in Figures 21 and 22 provide further guidance to finally achieve co-precipitated NMC precursors with the correct composition of commercial products in a slightly alkaline pH region (7.6-8.0) where the precipitation percentages of Ca ²⁺ and Mg ²⁺ remain low. Guidance is provided on how to prepare initial NMC solutions with high Mn ²⁺ concentrations.

Figure 20 shows the relationship between the NMC ratio in the initial solution and the NMC ratio in the final solid at various precipitation pHs. The NMC ratio of the initial solution varied from NMC 6:2:2 to 6:3:2 and 6:4:2, which corresponds to the Mn This is because the precipitation rate of ²⁺ is lower than that of Ni ²⁺ and Co ²⁺ . For laboratory practice, it is difficult to initially maintain accurate NMC ratios using analytical metal sulfates with different hydration values. Therefore, the Y-axis in Figure 20 displays the exact initial NMC ratio, sample name and corresponding final precipitation pH corresponding to NMC 6:2:2, 6:3:2 and 6:4:2, while the Shows the ratio of NMC precursor to final NMC. Results showed several NMCs consistent with the commercial NMC 622 composition, including sample 8 (pH 9.32), NMC 44 (pH 9.2), NMC 47 (pH 8.63), NMC 37-4 (pH 8.08), and NMC 49 (pH 7.7). It shows that a precursor has been created. There are also many NMC precursors whose final NMC ratios match commercial NMC 532, including NMC 37-2 (pH 8.06), NMC 52 (pH=7.9), and NMC 50 (pH 7.77).

battery material manufacturing

The purified solution from the leaching process was used to precipitate NMC 622 precursor. Specific NMC co-precipitation conditions are provided in the experimental section below. Thereafter, the obtained precursor was lithiated and calcined to prepare NMC 622 anode material. The battery performance of this NMC 622 cathode material can match that of commercial NMC 622 cathode material.

Experiment - NMC precipitation process

Specifically, the leaching solution ( Sample 8 - Leach ), purified solution ( Sample 8 - Purification ) and final solution ( Sample 8 - Final ) of the leaching process are presented in Table 16. To meet the chemical composition of the NMC 622 precursor, extra Ni and Mn sulfate salts were added to the purified solution ( Sample 8-Tablet ) to produce Sample 8-Final Solution, which was used directly for NMC precipitation.

Table 16: Solution assays for solutions (leaching, purification and final solution)

500 mL of NMC initial solution (0.2 M total NMC) was fed into a 1 L reactor containing 200 mL of ammonium solution (0.1 M) by a peristaltic pump at a rate of 8 mL/min. After 3 minutes, 480 mL of alkaline solution (0.208 M) began to be pumped into the same reactor at the same flow rate. After 60 minutes, all liquid was pumped into the reactor. Mixed in a 1 L reactor using an overhead mechanical stirrer at 800 rpm. A hot plate was used to heat the reactor to 80° C. under an inert N ₂ atmosphere. The precipitation retention time is in the range of 8-10 hours.

Afterwards, the reactor was cooled from 80°C to room temperature. The final slurry was filtered by vacuum filtration to obtain a precipitate. The final solution pH (or final pH) is 9.32. The obtained precipitate was subjected to two-step washing. The first wash was performed by repulping the sediment with 0.1 M NaOH solution (∼5% solid content) using magnetic stirring for 60 min at 80°C, followed by solid/liquid separation using a vacuum filter. For the second washing, the sediment from the first washing was repulped with a 2% NH ₃ H ₂ O solution (~5% solid content) using magnetic stirring at 80°C for 60 minutes, and then separated into solids/solids using a vacuum filter. The final NMC precursor solid was obtained by liquid separation. The NMC precursor was then dried in an oven at 105°C for 8-10 hours, and could be sent to battery manufacturing. The final NMC ratio from the precursor is 5.8:2.2:2.1, which is in the range of 6:2:2. The analysis is provided in Table 17.

Table 17 : Degree of NMC precipitation and solid analysis of NMC precursor before and after washing (impurity content measured in parts per million (ppm); Ni, Co, Mn contents measured in weight percentage, wt%)

Results - Battery Performance

The NMC activator is prepared by lithiating the NMC precursor obtained by the above-described method. The precursor is first mixed with a 5 wt.%-excess stoichiometric ratio of Li ₂ CO ₃ as the lithium source. In the calcination process, the mixture is first precalcined at a low temperature of 400-500℃ for 1 hour, then pulverized again, and then calcined at a high temperature of 850-900℃ for 10 hours in an air atmosphere. A negative electrode is prepared by dispersing NMC active material (80 wt.%), carbon black (10 wt.%) and polyvinylidene fluoride (10 wt.%) in N-methyl-2-pyrrolidinone. Afterwards, the slurry is applied on aluminum foil and dried at 100°C for 24 hours. The electrolyte used is LiPF ₆ (1 M) in EC/DMC (mass ratio 1:1). The cell is then packed in an argon-filled glove box with a lithium metal anode, and its electrochemical performance is tested over a voltage range of 3.0-4.4V.

The battery performance of the Sample 8 cathode at 0.2C is shown in Table 18, where the initial specific capacity of the sample was approximately 163 mAh/g (baseline: 170 mAh/g) and the capacity remained above 163 after 6 cycles. Battery performance is similar to commercial NMC 622 batteries with capacities in the range of 165-170 mAh/g at the same charge-discharge rate. The sample cathode also shows an excellent crystal structure with hexagonal arrangement and low Ni-Li mixing.

Table 18 : Battery performance for three individual batteries using Sample 8 cathode at 0.2C.

Example 3: Precipitation in the presence of impurities

A mixed precipitate containing nickel, manganese and cobalt (NMC) was produced from various solutions in the presence of a wide range of impurities. The methodology used was able to prevent precipitation of some or all of the impurities present and produce co-precipitates with electrochemical properties despite the presence of these impurities in the initial solution.

Tables 19-32 contain the aqueous feed solution and post-co-precipitation supernatant ratios from a series of NMC precipitation tests. When interpreting these values, keep in mind that this is an NMC:impurity ratio, so smaller numbers indicate higher impurity levels relative to NMC. Therefore, a decrease in the ratio after precipitation is evidence of selectivity. Therefore, the results shown in the table show the selectivity for each element.

Table 19 Table 20

Table 21 Table 22

Table 23 Table 24

Table 25 Table 26

Table 27 Table 28

Table 29 Table 30

Table 31 Table 32

Table 33 shows the concentration (NMC:element ratio) of aqueous feed solutions (i.e., before co-precipitation) of a wide range of elements. The table also includes a battery of tests to demonstrate that these solutions can produce acceptable co-precipitates with electrochemical performance.

Table 33

Example 4 : commercial scale

The co-precipitation process has been demonstrated on a commercial scale. Table 34 details the starting solution concentration (aqueous feed solution concentration) for each element and the associated ratio for nickel.

Table 34

This solution was co-precipitated using a substoichiometric volume of sodium carbonate as precipitant. In this process, less than the stoichiometric amount of base was used to prevent most of the Ca and Mg from precipitating. Using this method, the precipitation extents of Ni, Mn, and Co are 95%, 80%, and 95%, respectively. Therefore, in order to produce a material that met the specifications, an additional amount of Mn had to be included in the starting solution.

The co-precipitate from this process was subjected to a series of water and alkali washing steps to remove Na and S. The final resulting mother liquor and washed solid assays are shown in Table 35.

Table 35

Based on these final solutions and solid compositions, a clear separation between NMC and impurity elements such as Ca, Mg, Al, Cu, Cr, Fe, K, Na, P, and S can be seen. The industrial scale highlights one methodology detailed in the patent that precipitates NMC in the presence of impurities with selectivity for NMC for some or all of the impurity elements. This material was lithiated and calcined to form a battery. This battery demonstrated electrochemical performance and achieved an initial capacity of 163 mAh/g.

Example 5: commercial scale

The process described in Example 4 was repeated including the aging process during NMC precipitation. Table 36 details the starting concentrations and associated ratios for nickel.

Table 36

This solution co-precipitated with stoichiometric base and non-excess Mn. After co-precipitation, the solution was aged in a tank for 48 hours. This had the advantage of increasing the separation efficiency of Mg and Ni by re-dissolving part of the precipitated Mg. Additionally, this method also allows for a greater degree of control over the degree of precipitation of Mg, which is often added to NMC products as a dopant to improve cycling stability. The composition of the products produced by this process is shown in Table 37. This material was lithiated and calcined to form batteries for electrochemical testing. As a result of the battery test, the initial capacity was 170 mAh/g.

Table 37

Example 6 : Directly manufacture NMC by processing Ni-laterite ore

Leaching:

Nickel laterite ore samples were leached using sulfuric acid to produce a solution suitable for direct production of NMC precursor material. The assays for the materials used are shown in Table 38. The leaching conditions used were 1:1 Mg:H ₂ SO ₄ (on molar basis), 10% dry solids loading, 6 hours at 80°C. After leaching, 90% of nickel, 80% of magnesium and various amounts of impurity elements were recovered into solution. The recoveries of all major elements are shown in Figure 23 and the compositions of the leaching solutions are shown in Table 39.

Table 38 - Nickel laterite elemental composition

Table 39 - Laterite ore leaching solution composition

Remove impurities:

The pH of the solution was then used to remove impurities to the level required to use selective co-precipitation. This was achieved by heating the filtrate obtained from the previous leaching step and increasing the pH using sodium carbonate solution. Air was sprayed into the reactor to oxidize iron and promote precipitation as ferric iron. As the single state was not sufficient to accomplish this, a second step was performed using 30% H ₂ O ₂ as an oxidizing agent. The solid was then separated from the purified solution. The experimental conditions used were 75°C at pH 5.5, held for 1 hour, 200 g/L Na ₂ CO ₃ as a base, air, and 30% H ₂ O ₂ added as an oxidizing agent in the second step. The composition of the final purified solution is shown in Table 40.

Table 40 - Solution composition after purification

NMC co-precipitation:

Before NMC precipitation, the concentration of Ni was increased to 2 g/L, and cobalt and manganese were adjusted so that the solution had a 6:4:2 Ni:Mn:Co molar ratio. This ratio adjustment was performed using sulfate. NMC precipitation was completed according to the following procedure: 15% Na ₂ CO ₃ administered for 6 hours and then maintained overnight. Repeated a second time: 75°C; Final pH 7.39. The solution concentrations of major elements before and after this process are shown in Table 41.

Table 41 - Solution concentration before and after NMC precipitation

The co-sediment was washed using a three-step washing process including water displacement wash, water repulp wash, sodium hydroxide repulp wash and mild ammonia wash. The overall recovery of each major element after the process was completed is shown in Figure 24. The composition of the resulting final solid is shown in Table 42. These results clearly show the high selectivity of Ca/Mg for NMC even when the Mg concentration is significantly larger than that of the NMC metal. This allows low-grade NMC metal sources, such as laterites, to be used directly for NMC manufacturing.

Table 42 - Solution concentration before and after NMC co-precipitation

Battery test results:

Three cathodes were prepared from NMC co-sediment samples. The initial capacity generated was 75 mAh/g, and the capacity maintenance rate after 20 cycles was 84%.

Example 7: Directly manufacture NMC by processing mixed sulfide product ore

Leaching:

Sulfide-enriched samples were leached using sulfuric acid and air to create a solution suitable for direct production of NMC precursor materials. The specifications of the materials used are presented in Table 43. The experimental conditions used were as follows: 80°C, 4 days, 10% dry solids loading, H ₂ SO ₄ dosed to maintain pH at 2, air flow rate 0.5 L/min. After leaching, 30% of the nickel and various amounts of impurity elements were recovered. The recoveries of all major elements are shown in Figure 25 and the composition of the leaching solution is shown in Table 44.

Table 43 - Elemental Composition of Sulfide Concentrate Samples

Table 44 - Leaching solution composition after sulfuric acid leaching of sulfide concentrates

Remove impurities:

The pH of the solution was then used to remove impurities to the level required to use selective co-precipitation. This was achieved by heating the filtrate obtained from the previous leaching step and increasing the pH using sodium carbonate solution. Air was sprayed into the reactor to oxidize iron and promote precipitation as ferric iron. The experimental conditions used were as follows: 75°C, pH increased sequentially from 3 to 4 and 5.3 to 6, 200 g/L of Na ₂ CO ₃ as base, and air sparging as oxidizing agent.

NMC precipitation:

Before NMC precipitation, the Ni concentration was increased and the concentrations of cobalt and manganese were adjusted so that the solution had a 6:3:2 Ni:Mn:Co molar ratio. This ratio adjustment was performed using high purity sulfate. NMC precipitation was completed according to the following procedure: 5% Na ₂ CO ₃ for 6 hours and then maintained overnight at 75°C, final pH 7.85. The solution concentrations before and after this process are shown in Table 45.

Table 45 - Solution concentration before and after NMC precipitation

The co-precipitate was then washed using a three-step washing process including water displacement wash, water repulp wash, sodium hydroxide repulp wash and mild ammonia wash. The overall recovery rate of each major element after completion of the process is shown in Figure 26. The composition of the final solid produced is shown in Table 46.

Table 46 - Solid composition of final washed NMC solids

Example 8 : Example of mixed leaching of cobalt concentrate and black mass

A 50% blend of cobalt concentrate and black mass was leached using SO ₂ to produce a solution suitable for direct production of NMC. The assays of the materials used are shown in Table 47. The experimental conditions used were as follows: 55°C, 2 hours 40 minutes, 5% dry solids loading, SO ₂ sparging to provide 200% stoichiometric dose over 2 hours. After leaching, 30% of the nickel and various amounts of impurity elements were recovered. The recoveries of all major elements are shown in Figure 27 and the composition of the leaching solution is shown in Table 48.

Table 47 - Elemental composition of 50% cobalt concentrate 50% black mass blended samples

Table 48 - Leach solution composition after sulfuric acid leaching of blended cobalt concentrate/black mass

Afterwards, the pH of the solution was increased to 5.5 while sparging air. These conditions should be maintained for at least 1 hour to allow sufficient time for Fe to precipitate. Using this process, selective precipitation is possible by sufficiently removing impurities such as Al, Fe, Cu, Cr, and Zn. This solution should have the molar ratio of Ni, Mn and Co adjusted to 6:2:2 to be suitable for NMC production.

Example 9: Washing of co-precipitate

Immediately after co-precipitation, the solids formed are subjected to sequential washing procedures that may include water, basic (carbonate, hydroxide or ammonia) or acid washing. The exact cleaning method selected will depend on the impurities present. In this example, a batch of approximately 1 tonne of wet NMC was produced on a commercial scale. This was then washed with water at a ratio of 60:1 water:solids by dry mass, followed by a caustic soda re-slurry wash at 7% solids using a 10% sodium hydroxide solution, followed by a 40:1 water:dry solids by mass basis. A final water wash was performed at a rate of A test of this sequential procedure is shown in Table 49. The washing step was successful in removing some impurity elements and improving the NMC:impurity ratio for impurity elements such as Ca, Cu, K, Mg, Na, S, and Zn.

Table 49

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains.

In this specification and claims (if any), the word 'comprising' and its derivatives, including 'comprise' and 'comprise', include each of the recited integers but do not exclude the inclusion of one or more additional integers.

Reference throughout this specification to “an implementation” or “an implementation” means that a particular feature, structure, or characteristic described in connection with that implementation is included in at least one implementation of the invention. Accordingly, the phrases “in one implementation” or “in an implementation” appearing in various places throughout the specification do not necessarily all refer to the same implementation. Additionally, specific features, structures, or properties may be combined in one or more combinations in any suitable manner.

In accordance with the law, the invention has been described in more or less specific language as to its structural or methodological features. It is to be understood that the invention is not limited to the specific features shown or described, since the means described herein include preferred forms of carrying out the invention. The invention is therefore claimed in any form or modification within the appropriate scope of the appended claims (if any) as properly interpreted by those skilled in the art.

Claims (23)

A method of producing a co-precipitate, the co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising:
(i) providing an aqueous feed solution comprising the at least two metals and at least one impurity, wherein the at least one impurity is arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead. , silicon, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, and niobium. or a step selected from the group consisting of a combination thereof; and
(ii) adjusting the pH of the feed solution to between about 6.2 and less than 10 to produce (a) a co-precipitate comprising the at least two metals; and (b) providing a supernatant comprising the at least one impurity. 2. The method of claim 1, wherein the molar ratio of at least two metals to total impurities in the aqueous feed solution is less than 200,000:1. 2. The method of claim 1, wherein the molar ratio of at least two metals to total impurities in the aqueous feed solution is less than 200:1. 4. The method of any one of claims 1 to 3, wherein the molar ratio of at least two metal to alkaline earth metal impurities in the aqueous feed solution is less than 200:1. 5. The method of any one of claims 1 to 4, wherein the molar ratio of the at least two metals to metal and metalloid impurities is less than 500,000:1. 6. The method of any one of claims 1 to 5, wherein in step (ii) the pH of the feed solution is adjusted to about 6.2 to 9.2. 7. The method according to any one of claims 1 to 6, wherein before step (i), the method comprises:
Provided is a feed mixture comprising at least one metal selected from nickel, cobalt and manganese, said feed mixture being one of an oxidized feed, a reduced feed or a non-oxidized feed, wherein:
The oxidized feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2;
The reduced feed has more of the at least one metal in an oxidation state of less than 2 than in an oxidation state of greater than 2, or has substantially all of the at least one metal in an oxidation state of 2 and at least one of the metals in sulfide form. Have at least some of it; and
wherein the unoxidized feed has substantially all of the at least one metal in oxidation state 2 and substantially no of the at least one metal in sulfide form;
The feed mixture is treated with an aqueous solution to form a leachate comprising the at least one metal, wherein the pH of the aqueous solution is such that the pH of the leachate is from about -1 to about 6, wherein:
If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and
If the feed mixture is a reduced feed, the treatment further includes adding a reagent comprising an oxidizing agent;
The leachate thereby contains at least two metals in an oxidation state of 2,
wherein the leachate is used to provide an aqueous feed solution.
Method, including. 8. The method of any one of claims 1 to 7, wherein the feed solution comprises Co(II), Mn(II) and Ni(II). 9. The method of any one of claims 1 to 8, wherein the feed solution in step (i) has a pH of 2.0 to 4.0. 10. The method of any one of claims 1 to 9, wherein step (i) comprises separating the feed solution using at least one separation technique selected from the group consisting of decanting, centrifugation, filtration, cementation and sedimentation, or combinations thereof. A method comprising separating solid impurities from. 11. The method of any one of claims 1 to 10, wherein step (i) comprises dissolution from the feed solution using at least one separation technique selected from the group consisting of ion exchange, precipitation, adsorption and absorption, or combinations thereof. A method comprising removing impurities. 12. The method of any one of claims 1 to 11, wherein the ratio of nickel, cobalt and manganese is adjusted by adding one or more of cobalt, manganese and nickel to the feed solution to provide the desired molar ratio in the co-precipitate. A method further comprising the step of adjusting. 13. The method of claim 12, wherein the desired ratio is about 1:1:1 nickel:cobalt:manganese. 13. The method of claim 12, wherein the desired ratio is about 6:2:2 nickel:cobalt:manganese. 15. The method of any one of claims 1 to 14, further comprising decanting and/or filtering to separate the co-precipitate. 16. The method of claim 15, comprising at least one step of washing the co-precipitate. 17. The method of claim 16, wherein the at least one washing step uses an alkaline, water, acid or ammonia wash. 18. The method of any one of claims 1 to 17, further comprising adding lithium to the co-precipitate. 19. The method of any one of claims 1 to 18, comprising drying the co-precipitate. 20. The method of claim 19, wherein the drying occurs at a temperature of about 80° C. to about 150° C. and/or the drying is performed for at least 5 hours. A co-precipitate of at least two metals selected from nickel, cobalt and manganese, produced by the method of any one of claims 1 to 20. A method of producing a co-precipitate, the co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising:
(i) providing an aqueous feed solution comprising the at least two metals and at least one impurity; and
(ii) adjusting the pH of the feed solution to about 6.2 to about 11 to produce (a) a co-precipitate comprising the at least two metals; and (b) providing a supernatant comprising the at least one impurity. A method for producing leachate comprising at least two metals selected from nickel, cobalt and manganese, said method comprising:
A. Providing a feed mixture comprising at least two metals, wherein the feed mixture is one of an oxidized feed, a reduced feed, or a non-oxidized feed, wherein:
The oxidized feed has more of at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2;
The reduced feed has more of the at least two metals in an oxidation state of less than 2 than in an oxidation state of greater than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least two metals in sulfide form. have at least some of; and
wherein the unoxidized feed has substantially all of the at least two metals in the oxidation state of 2 and substantially none of the at least two metals in sulfide form;
B. treating the feed mixture with an aqueous solution to form a leachate comprising the at least two metals, wherein the pH of the aqueous solution is such that the pH of the leachate is from about 1 to about 7, wherein:
If the feed mixture is an oxidized feed, the treatment further comprises adding a reagent comprising a reducing agent; and
If the feed mixture is a reduced feed, the treatment includes steps further comprising adding a reagent comprising an oxidizing agent;
whereby the leachate contains at least two metals in an oxidation state of two.

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